• 한국해양공학회지
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• 제8권2호
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• pp.157-165
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• 1994

Effect of an accelerated iso-thermal aging (375 degree C x 66days, 375 degree C x 200days) on elastic-plastic fracture resistance curve were examined in SA533B low alloy steel. Fracture toughness test are conducted by unloading compliance method at room temperature. But the apparent negative crack growth phenomenon, usually arise in partial unloading compliance test. The phenomenon of negative crack growth may be eliminated by the offset technique. There is no effect of aging on J sub(IC) and dJ/da in iso-thermal aged (375 degree C x 66 days) specimen, but there is very little effect in iso-thermal aged (375 degree C x 200 days) specimen.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권1호
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• pp.65-68
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• 2005

Growth and development of a plant over a growing season is closely related to the daily accumulation of heat. Heat unit measured by accumulated growing degree days (GDD) is becoming increasingly popular to estimate the growth of a plant or even in insect. GDD or heat accumulation per day is measured by calculating average daily temperature and then subtracting the base temperature below which growth does not occur. Heat accumulation per day is added for the desired period and accumulated GDD is determined. The present study was conducted in five seasons in an established garden with K-2, S-36 and V-1 mulberry varieties belonging to Morus indica L. grown under completely irrigated condition at the farm of CSRTI, Mysore during 2001 - 2002. Plants were pruned in each season and the growth of the plant measured by total shoot length and fresh leaf yield was recorded at an interval of 5 days starting from 30 days of pruning (DAP) to 70 days when all the plants were pruned. The accumulated GDD for the corresponding days were recorded and used for analysis. Accumulated growing degree days (GDD) have been found to be perfectly correlated with both growth and yield in all the seasons in all the varieties studied. The high $R^2$ values indicated a strong relationship between the accumulated GDD and, growth and yield of mulberry.

• 전기학회논문지
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• 제66권5호
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• pp.745-749
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• 2017

Climate change and energy security are major factors for future national energy policy. To resolve these issues, many countries are focusing on creating new growth industries and energy services such as smartgrid, renewable energy, microgrid, energy management system, and peer to peer energy trading. The financial and economic evaluation of new energy services basically requires energy savings estimation technologies. This paper presents the baseline load estimation method, which is used to calculate energy savings resulted from participating in the new energy program, using moving average model with heating degree days (HDD) and cooling degree days (CDD) adjustment. To demonstrate the improvement of baseline load estimation accuracy, the proposed method is tested. The results of case studies are presented to show the effectiveness of the proposed baseline load estimation method.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.507-513
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• 2006

Changes of in vitro true digestibility (IVTD) of Napiergrass (Pennisetum purpureum) were determined by a filter bag system, and their relationships to chemical composition, leaf to stem ratio, plant height, geographic location, climatic factors and harvest interval were studied and used to develop prediction models for the crude protein (CP), acid-detergent fiber (ADF), and neutral-detergent fiber (NDF) contents and IVTD. Partitioning the total variance of IVTD of Napiergrass showed that 80% was attributable to the effect of harvest interval. Days of growth, plant height, leaf/stem ratio, CP, ADF and NDF of Napiergrass had highly significant relationships (p<0.01) with IVTD. The highest coefficient of correlation between the ADF, NDF, and IVTD of Napiergrass and growth degree days was obtained when the base temperature was set at $0^{\circ}C$. Growth degree days could predict ADF, NDF, and IVTD of Napiergrass more accurately than plant height, and plant height is not suitable to predict IVTD.

• 한국작물학회지
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• 제44권3호
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• pp.282-287
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• 1999

The object of this study was to determine the difference of the time course changes of transpiration, diffusion resistance and photosynthetic rate of rice at several different growth stages subjected to soil moisture stress (SMS) and recovery by irrigation. A japonica rice cultivar 'Dongjinbyeo', was grown under flooded condition in a plastic container filled with silty loam soil. At 5 main growth stages, the container was treated by SMS until initial wilting point (IWP) and then reirrigated. The duration of SMS until IWP were the longest, 13 days for tillering stage, and the shortest, 7 days for panicle initiation and meiosis stage. The transpiration rate rapidly decreased during SMS and the transpiration rate at IWP of the stressed plant showed 10∼20% compared with control, and the transpiration rate of stressed plant at most growth stages also recovered rapidly after irrigation and then reached 100% of control within a week. The shoot photosynthetic rate in all growth stages rapidly decreased by SMS, and the rates at IWP of stressed plants were de-creased nearly to 0%, beside the treatment at tillering stage. The recovery degree of photosynthetic rate by irrigation ranged from 20 to 90%, showed higher at early growth stages of SMS treatment than that of later stages. At all growth stages the leaf diffusion resistance of stressed plants was over 3 times that of the control resulting from a rapid increase at 3 to 5 days after draining for SMS, and showed quick recovery by irrigation within 3 days after drainage. The above physiological parameters changed in close relation with the decrease of the soil matric potential after SMS. These results indicate that at all main growth stages of rice plants the transpiration and photosynthesis reduction by stomatal closure reponded sensitively to the first stage of SMS closely related with decrease of soil water potential, while those recovery pattern and recovered degree by irrigation are little different by growth stage of rice.

• 한국농공학회지
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• 제28권2호
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• pp.31-41
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• 1986

Knowledge of the degree of yield reduction due to water stress at different crop growth stages in rice production is important for rational scheduling of irrigation during periods of insufficient water supply. Previous studies to determine the degree of yield reduction duo to water stress suffered from interruptions by rain during experiment. Also the findings did rot relate the degree of water stress to the soil water potential and water deficit status of rice plants. In this study, two years experiments were conducted using the high yielding rice varieties, an Indica x Japonica (Nampoong) and a Japonica variety(Choochung). These were grown in 1/200$^{\circ}$ plastic pots placed under a rainfall autosensing, sliding clear plastic roof facility to control rainfall interruptions. The results obtained were as follows. 1.The two varieties differed in the growth stage most sensitive to water stress as well as the degree of yield reductions. When rice plants were stressed to the leaf rolling score 4 and soil water potential of about - 20 bar at major crop growth stages which included heading, booting, non-effective tillering, panicle initiation and early tillering stages, the yield reductions in the Indica x Japonica variety were 58%, 34%, 27%, 22%, and 21%, respectively, whereas in the Japonica vairety they were 23%, 36%, 1%, 13% and 22%, respectively. This result show that the recommended drainage during non-effective tillering is valid only for the Japonica variety. Sufficient irrigation at booting, heading and early tillering stages are necessary for both varieties. 2.The two varieties showed visible wilting symptoms when the soil water potential dropped to about - 3.0 bar. The Japonica variety showed more leaf rolling than the Indica X Japonica. However, it had a higher retention of leaf water content and greater stomatal diffusive resistance. When the soil water potential dropped, the Japonica variety showed leaf rolling score (LRS) 1 at 0 soil-5. 0 bar and LRS 2 at 0 soil -6.0 bar while the Indica X Japonica showed LRS 1 at 0 soil - 5.5 bar and LRS 2at 0 Soil - 9.0 bar. The stomatal diffusive resistance was maximum at the second top leaf blade in both varieties at intermediate water stress of 0 soil - 4.5 bar. 3.The number of days that was required for the soil water potential to drop to-3. 0 bar and to - 20.0 bar after drainage of irrigation water from the 20cm deep silty clay loam soil in the pots were 6 and 13 days, respectively for booting stage, and 7 and 11 days, respectively for heading stage, 9 and 12 days, respectively for panicle initiation stage, and 12 and 19 days, respectively for early tillering stage. 4.Water stress during the early tillering stage recorded the longest delay in beading time, the largest reduction in panicle numbers and a substantial yield decrease of 20%. This calls for better water management to ensure the availability of water at this stage, particularly during drought periods. In addition, a reexamination of the conventional inter-drainage practice during the non-effective tillering stage is necessary for the high yielding Indica X Japonica varieties.

• 대한한의학회지
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• 제27권4호
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• pp.162-173
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• 2006

The water-extracts of Scutellaria barbata Don (SBDE) were isolated from Chinese medicinal plant sources. The extracts showed strong growth-inhibitory activity and cancer chemopreventive activity on the growth and DNA incorporation of MG63 human osteosarcoma and K562 human leukemia cell lines. The growth of human cancer cells was inhibited in the presence of the extracts (20, 50 and 100 ${\mu}$g/ml), and the effects were concentration-dependent and incubation time-dependent up to 8 days. When 50 ${\mu}$g/ml of the extracts was added to the media of MG63 and K562, cell growth after 8 days or 6 days of incubation was retarded by 93.2 to 97.3% of the control group. Morphological changes of MG63 and K562 cell lines were observed. As the concentration of the extracts increased up to 50 ${\mu}$g/ml, degree of cell aggregation decreased. Moreover, the DNA incorporation of the cells which were labeled with [3H] thymidine was significantly reduced after 3 days of incubation at $37^{\circ}C$ with the extract. Therefore, it is suggested that the extract is highly effective on inhibition of cancer cell growth. The extract also inhibited gene expression of IGF-II in transcriptional level. Since IGF-II works as a mitogenic effector on MG63 and K562 cell lines, these results suggest that the growth inhibition is in part mediated through the inhibition of IGF-II gene expression.

• 생물환경조절학회지
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• 제27권4호
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• pp.424-430
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• 2018

본 연구는 고추의 생육특성인 초장, 엽면적, 생체중, 건물중을 조사하였고, 기상요인에 따른 수량 예측 모델개발을 위하여 수행되었다. 생육도일온도에 따른 고추의 생체중, 건물중, 초장 및 엽면적에 대한 생장 모델(시그모이드 곡선)을 개발하였다. 고추는 정식 후 50일전후로 초장, 엽면적, 생체중 및 건물중이 지수 함수적으로 증가하였으며, 140일 이후에는 생장요인들이 평행을 이루었다. 그리고 생육도일온도에 따른 고추의 생장을 분석 한 결과 지수 함수적으로 생장이 늘어나는 시점의 GDD는 1,000였다. 고추의 건물중에 대한 상대생장 속도를 계산하는 식은 RGR $(dry\;weight)=0.0562+0.0004{\times}DAT-0.00000557{\times}DAT^2$ 였다. 수확한 적과의 생체중과 건물중으로 고추의 단수를 구하였을 때, 정식 후 112일에 1,3871kg/10a였고, 건고추의 단수는 정식 후 112일에 291kg/10a이였다. 고추 작황예측 프로그램 개발을 위해서는 고추의 생산성에 관여하는 주요요인을 분석하고, 실시간으로 계측한 생육 및 기상자료를 기반으로 하여 생육모델을 보정 및 검증해야 할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.451-461
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• 1993

Four hundred and eighty broiler chicks of both sexes were obtained from commercial hatchery (Hubbard) and raised on floor pens. All chicks were allowed free access to food from 0 to 7 and 20 to 56 days of age. At 7 days of age, all broilers were weighed individually, and divided into five groups as follows: 1. feed ad libitum as the control; 2. allowed free access to food 3 days and starved 1 day ($3{\times}1$); 3. allowed free access to food 2 days and starved 1 day ($2{\times}1$); 4. allowed free access to food 1 day and starved 1 days ($1{\times}1$) and; 5. allowed free access to food 2 days and starved 2 days ($2{\times}2$). Broilers were restricted for 12 days (d 7 through 17) of a 56-day trial. Broilers were fed a commercial starter diet (crude protein 23.8% and ME 3,070 kcal/kg) for 21 days, and commercial finisher diet (crude protein 20% and ME 3,160 kcal/kg) from 22 to 56 days of age. Although there was compensatory growth in some groups, (the $1{\times}1$ female group, and the $3{\times}1$ and $2{\times}1$ male grous), its level was not sufficient to achieve normal body weight at market age. There was sexual dimorphism for accelerated growth as well as differences in the ability to achieve a complete compensation of growth to the weight, feed conversion ratio, and body composition of ad libitum chicks. Early feed restriction could be used to reduce production cost because of the lower fed conversion ratio, mortality rate and the amount of starter diet consumed by broilers. The response of chicks to early feed restriction might depend on the degree of feed restriction, the method of feed restriction, duration of feed restriction, and sexes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.179-182
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• 2002

XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration