• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.87-98
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• 2011

Crack formations are inevitable in reinforced concrete structures. To estimate crack widths, empirical formulae are used widely and indirect crack controling methods of limiting bar spacing and bar diameter are also used due to their simplicity. In EC2, the characteristic crack width is calculated by multiplying maximum crack spacing and average strain. In this study, limit values of maximum bar spacing and bar diameter are examined as the material characteristics are varied. Two models of tension stiffening effect and maximum crack spacing and their effects are evaluated. The obtained results are compared with the values obtained using KCI method. The results showed that a significant difference is found when two tension stiffening effect are employed, and an under-estimation is found when 2nd order tension stiffening effect and maximum crack spacing limit from Part II were implemented. Therefore, a rational indirect crack control method attained using the tension stiffening effect of 2nd order form is needed. Also, a consistency in serviceabiliy analysis in flexural members needs to be secured. In order to achieve these goals, two crack controling models are suggested.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.571-578
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• 2002

In temporal database, extended time dimension for history management brings about complexity of join operation and increased cost. To solve this problem, a method that joins the divided segment time data after partition the time range into fixed time interval is introduced. But existing methods can't solve the ambiguity problem of time border that caused by temporal granularity in the partition point. In this paper, We suggested Fuzzy Minimum Interval Partition (FMIP) method that introduced the possibility distribution of fuzzy theory considered uncertainty time interval border in the partition line.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1880-1885
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• 2007

In this paper, we propose the method that improve the performance of the Mowse. Mowse is the tool of the peptide mass fingerprinting that is used the identification of protein. In Mowse, frequency factor matrix is generated to regular interval for protein and peptide mass and the value of each elements is calculated to frequency of peptide. We propose new method for calculation of exact scoring value maintaining same size of matrix. The proposed method is that decide interval of matrix considering distribution of protein database. That is, interval of matrix is decided to small in many value of protein mass and is decided to large in few value of protein mass. We present the performance result both Mowse scoring method and the proposed scoring method.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.106-106
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• 2023

저수지 수문자료는 강우량, 유입량, 저수량, 방류량이다. 이 중에서 관측되고 있는 것은 저수량과 일부 수로방류량에 불과하다. 그럼에도 모의에 의해 유입량을 고정시키면, 물수지에 의해 방류량을 계산할 수 있다. 그러나 저수량 오차로 모의 유입량과 계산 방류량의 신뢰도는 반드시 확인돼야 한다. 신뢰도가 낮으면 모의 유출량과 계산 방류량을 조정하며 신뢰도를 높여야 한다. 신뢰도는 평가주기가 짧을수록 보장된다. 여기서는 유역면적 218.80km², 유효저수량 3,494만m³, 수혜면적 5,117ha인 탑정지에 대해 2020년 1월1일부터 12월31일까지 1시간 단위로 1달, 10일, 3일, 2일 간격의 주기로 저수지 운영자료를 생산하고, 그 신뢰도를 평가하여 평가주기가 짧을수록 오차가 감소되는 것을 관찰코자 했다. 1시간 간격의 유입량은 ONE 모형으로 모의했고, 저수지 물수지 모형을 구축하여 모의 유입량에 저수량 변화를 더해 방류량을 계산했다. 또한 저수지 물수지에 의해 저수위를 모의했으며, 관측 저수위와의 오차제곱근(RMSE)으로 신뢰도를 평가한 결과는 다음과 같다. 1달 간격으로 신뢰도를 평가한 경우 RMSE는 132.466m, 10일 간격은 46.922m, 3일 간격은 0.520m, 2일 간격은 0.349m로 나타났다. 위의 결과로부터 저수지 수문자료의 평가주기를 짧게 할수록 신뢰도는 개선된다고 말할 수 있다. 이상의 결과는 과거 자료에 대해 1년 동안 1시간 간격으로 유입량을 모의하고 방류량을 계산한 결과를 고정시키고, 평가주기를 달리하며 수위오차를 분석한 결과이다. 만약 평가주기별로 유입량과 방류량을 실제 상황에 적합하게 조정하면, 그 신뢰도는 훨씬 더 개선될 것이다. 현재 저수지 수위만을 관리하고 있는 현장의 상황에서 이 연구결과가 시사하는 바는 매우 크다. 첨언하면 AI 시대의 핵심은 자료다. AI의 먹이는 자료다. 다시 말해 자료 없는 AI는 시체와 같다. 자료는 기본이고 진실이다. 자료 없는 결과는 가짜다. 또한 위의 결과는 자료는 상시 관찰돼야 한다는 것을 말한다. 1년에 한 번 수문자료를 평가하는 제도로는 고품질의 자료를 생산할 수 없다. 무엇보다 자료는 상시 관찰하는 제도가 정착돼야 하며, 그 때 비로소 AI와 공존과 협력으로 물관리 기술의 혁신을 이룰 것이라 확신한다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.301-306
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• 2008

This experiment was conducted to compare the agronomic characteristics, productivity of silage com and barley cropping, forage sorghum and barley cropping in accordance with Drainage Culvert Spacing at poorly drained paddy field in National Institute of Animal Science, at Seonghwan in Korea, March 2006 to May 2007. The emergency and flowering date were no different among treatments. Emergency rate and flowering date were 90% and July 26 in silage com, 91% and July 21 in forage sorghum, 92% and April 27 in barley, respectively. Dry matter yield was high in line with 3 m drainage culvert spacing (24,389 kg/ha) > 5 m (23,543 kg/ha) > 7 m (21,527 kg/ha) > 0 m (14,132 kg/ha). In cropping systems, dry matter yield of forage sorghum and barley (22,111 kg/ha) was higher than silage com and barley (19,684 kg/ha). Crude protein and TDN yield were high in line with 3 m (2,365 and 15,394 kg/ha) > 5 m (2,255 and 14,513 kg/ha) > 7 m (1,884 and 13,747 kg/ha) > 0 m (995 and 8,682 kg/ha). In cropping systems, crude protein and TDN (total digestible nutrients) yield of forage sorghum and barley cropping system (2,165 and 13,582 kg/ha) was higher than silage com and barley cropping system (1,576 kg/ha and 12,482 kg/ha), respectively. Consequently proper drainage culvert Spacing at poorly drained paddy field was 5 m with forage sorghum and barley cropping system.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.133-140
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• 1993

A study was conducted to investigate the concentrations of Ca, P and ash in metatarsal bone of broiler chicks exposed to UV light in different Interval. Day-old Hubbard broiler chicks (199＝10 control＋3 irradiation interval $\times$ 9 elapsed time $\times$ 7 replicate) were fed vitamin D3 deficient diet for 3 wk in a windowless subdued-light room and exposed to 297 nm UVB light by 0.068 mJ/$\textrm{cm}^2$ three times In 0, 12 or 24 h interval. The metatarsal bones were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, separated from adhering tissue, ether extracted, dried and ashed. The Ca concentration was measured by atomic absorption spectrophotometry and P by ammonium metavanadate colorimetry. When the birds were continuously exposed to UVB light for 30 min without interval, the Ca content in metatarsus increased gradually according to the time after irradiation and reached the highest value 16.75% at 240 h after exposure. The P content also increased gradually until 144 h, where it was 9.75%. The ash content in metatarsus increased continuously until 240 h, the final time in this research, where 42.75% was shown. As 10 min three times irradiation in 12 h interval was applied to the chicks, the metatarsal Ca presented a small peak(13.31%) at 12 h after irradiation and a large peak(16.91%) at 144 h. P content showed a small peak(7.18%) at 12 h and a large level(8.34%) at 240 h. Ash content increased continuously until 240 h, where it was 46.53%. The small peaks in Ca and P concentration were thought to be derived from preirradiation at 12 and 24 h before final irradiation for 10 min. When 24 h interval system was treated, the peak value of Ca content(24.18%) occurred earlier(96 h) than those in 0 and 12 h interval systems. P content also showed the maximum value at 96 h(7.29%). Ash content presented an increasing trend until 240 h, where 45.75% was appeared. In respecting the method of UVB irradiation, the peak value of Ca content in metatarsus appeared earlier in 24 h interval system than in other systems. Meanwhile the ash contents in metatarsus of birds exposed to UVB light in 12 and 24 h interval procedures were higher than those in 0 h interval one. Therefore, it was concluded that a daily 10 min irradiation of UVB light would be desirable for increasing the Ca and ash content in metatarsus of brolier chicks.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.207-215
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• 2012

Structural behavior of built-up compression members with unsymmetric connectors under buckling status has been studied through these experiments. When the distance between adjacent H-300 beams of built-up compression member is 2 m in length, and the H-300 beams are lengthened up to 30 m in length with three-10 m-H-beams by bolts and double arrayed, three specimen having each connector interval 4 m, 5 m, 6 m are experimented for evaluating buckling loads. The buckling loads from the experiments are compared with buckling loads of structural analysis using FEM and buckling loads of Timoshenko Eq. loads in order to figure out how the connectors' interval affects on longitudinal and lateral displacements, also strain of the built-up compression members as well. The result shows that the buckling loads tend to sharply decrease non-linearly according to connectors' interval increases. As well as that, the differences between experimental buckling loads and theoretical buckling loads and between experimental buckling loads and structural analyses buckling loads also have a tendency to be increased as the connector interval increases.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.214-220
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• 2014

The aim of this study is to optimize the efficiency of a photobiorector on the growth rate of Chlorella vulgaris (C. vulgaris) by varying distance of optical panel (OP). The round shaped C. vulgaris (FC-16) having the size of $3-8{\mu}m$ is employed in this study. The cells of C. vulgaris are cultured in the Jaworski's Medium with deionized water at $22^{\circ}C$ for 15 days. The OP is placed at four different distances i.e., at 225 mm distance (Run 1), 150 mm distance (Run 2), 112.5 mm distance (Run 3) and 90 mm distance (Run 4) having a LED (Light Emitting Diode) source. The diffuse rate is achieved to 86%, 90%, 92% and 94% for Run 1, Run 2 Run 3 and Run 4, respectively. A narrower distance of OP caused to effectively to increase the efficiency of diffuse light rate. For mass cultivation of this biomass, medium is changed according to distance of OP after attaining a maximum biomass concentration; Run 1 in 8 days, Run 2 in 6 days, Run 3 in 4 days and Run 4 in 3 days. In addition, the amount of maximum biomass rate for Run 4 was reached 3 times higher than that of Run1. However, growth rate, chlorophyll per cell, cell volume and doubling time are found to be Run 3 and Run 4 higher than that of Run 1 and Run 2 samples. However, Run 3 and Run 4 are having a slight difference in all these measurements. These findings suggest that in terms of economic consideration and efficiency towards simultaneous mass cultivation of biomass, Run 3 was found to be more effective than other samples.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2703-2714
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• 2002

In this work, energy absorption characteristics and optimal welding space of spot-welded square hat type tube are investigated via quasi-static crush experiments and finite element (FE) analyses. A FE model reflecting the crush characteristics is established based on the experimentally observed crush mechanisms of specimens with welding spaces (20, 30 & 45 mm) and (25,40 & 55 mm) respectively for two specimen widths (60, 75 mm). The established FE model is then applied to other crush models of widths (50, 60 & 75 mm) with various welding spaces (20, 25, 30, 40, 45, 55, 75, 150, 300 mm) respectively. We examine the energy absorption characteristics with respect to the welding space for each specimen width. The outcome suggests an optimal spot welding space of square hat type thin-walled tube. Energy absorption is also presented in terms of yield strength of base metal, specimen thickness, width, and mean crushing force of spot-welded square hat type thin-walled tube.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.456-459
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• 2006

Effects of pork thickness (5 and 7 mm), heating temperature (190 and $220^{\circ}C$) and time (40-180 sec), and flipping interval (10 and 30 sec) during cooking against survival levels of general bacteria and pathogenic microorganisms in pork were investigated. Under same heating temperature and time, 10 sec interval of flipping was more effective in sterilizing bacteria than 30 sec interval. Bacteria was not detected in 5-mm thick pork cooked for 80 sec at $190^{\circ}C$ with 10 sec flipping interval, and 120 sec heating at $190^{\circ}C$ and 30 sec flipping interval. Bacteria were not detected in most 7-mm thick pork cooked for 100 sec at $190^{\circ}C$ with 10 sec flipping interval, and 180 sec heating at $190^{\circ}C$ and 30 sec interval. Bacteria were not detected in most 5- and 7-mm thick pork cooked for 80 sec at $220^{\circ}C$ with 10 sec flipping interval, and 120 sec heating with 30 sec interval.