• Journal of Biosystems Engineering
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• 제17권1호
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• pp.55-64
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• 1992

The aim of this study was to develop a phytotron for studying the effects of environmental factors such as temperature and humidity on plant growth. This equipment consists of the growth chamber, and the measurement and control system including control algorithms required for optimum operation. As the first step of the study, a temperature and humidity control system was developed. The results of this study are summarized as follows ; 1. Pt-100 was selected to measure temperature and a linearized op-amp circuit was developed for signal conditioning. 2. Pt-100 wet bulb thermometer based on Asmann's principle was developed to measure relative humidity. 3. Temperature and relative humidity conditions were controlled by ON-OFF and PWM operation using a PID controller. And an autotuning algorithm using the characteristics of step response was developed to determine optimal PID constants which were independent of the size of apparatus and environmental factors. 4. Under the ambient temperature of $20^{\circ}C{\sim}25^{\circ}C$, the temperature was kept within the error of ${\pm}0.3^{\circ}C$ in the range of $10^{\circ}C{\sim}40^{\circ}C$, and the relative humidity was kept within the error of ${\pm}5%$ in the range of ${\pm}50%{\sim}90%$.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.799-807
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• 2004

The objective of this field experiment was to investigate the growth, hay yield and chemical composition of cassava and stylo 184 grown under intercropping. The experiment was arranged in a Randomized Complete Block (RCB) design with 5 treatments and 4 replications. The treatments were: sole crop cassava (C); sole crop stylo 184 (S) and three intercropping treatments comprising an additive series of one (SC), two (SSC) and three (SSSC) rows of stylo 184 to one row of cassava. The results showed that leaf area per plant (LA) of cassava was significantly higher (p<0.05) in the sole crop relative to the intercropping treatments. Both total hay yield and CPDM yield were significantly higher (p<0.05) for C treatment and lower (p<0.05) for SSSC treatment. The total hay yield and CPDM yield were significantly greater (p<0.05) in the sole crop relative to the intercropping treatments. At the first and second harvests, CP content was similar among treatments; while at third and fourth harvests, CP contents were significantly greater (p<0.05) for the intercropping treatment relative to the sole crop. At the first and second harvest, NDF contents were significantly greater (p<0.05) in the sole crop relative to the intercropping treatments, whereas NDF contents were similar among intercropping treatments. Leaf area of stylo 184 at first and second harvest were significantly greater (p<0.05) for C, SC and SSC as compared with the SSSC treatments. At each harvesting, there were no significant differences in ash, CP, NDF, ADF and ADL contents of stylo 184 hay between the sole crop and intercropping treatments, except for the first harvest. ADF contents were significantly greater (p<0.05) in S, SC treatments relative to SSC and SSSC treatments. Both collective hay yield and CPDM yield of cassava and stylo 184 were significantly greater (p<0.05) for the SSC treatment and significantly lower (p<0.05) for the S treatment. Collective hay yield and CPDM yield were significantly greater (p<0.05) for the intercropping treatments relative to the sole crop. Based on this research, it was concluded that stylo 184 showed potential for intercropping with cassava. Intercropping cassava with stylo 184 has beneficial effects and can improve foliage biomass yield and soil fertility, which would be a more sustainable system than growing the cassava as a pure stand. In terms of hay yield and CP production, two rows of stylo 184 to one row of cassava could be the optimal pattern for this intercropping system.

• East Asian Economic Review
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• 제21권3호
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• pp.201-230
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• 2017

This paper studies the long-run behavior of relative price dispersion among cities in Korea with a special emphasis on heterogeneous transitional patterns of price level dynamics. Formal statistical tests indicate considerable evidence for rejecting the null of relative price level convergence among the majority of cities over the sample period of 1985-2015. The analysis of gravity model suggests that the effect of transportation costs on intercity price level differentials is limited, while other socioeconomic factors, such as income, input factor prices, demographic structure, and housing price growth, play key roles in accounting for persistent regional price level disparities. Individual price levels are found to be better explained by a multiple-component model, and the deviations from PPP may be attributed to distinct stochastic common trends that are characterized by income and demographic structure.

• 생물환경조절학회지
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• 제26권2호
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• pp.146-150
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• 2017

본 연구는 식물공장에서 미나리 재배시 명/암주기와 암기시간 동안의 상대습도 조절이 미나리의 생육과 품질에 미치는 영향을 알아보고자 수행하였다. 정식 후 30일째에 수확하여 생육 및 품질을 비교하였을 때 상대습도 60/90%(명/암기) 처리가 60/60% 처리보다 지상부 생체중이 뚜렷이 증가하였다. 상대습도60/60% 처리에서 명기가 연장될수록 지상부 생체중이 증가하였지만 60/90% 처리에서는 16/8h 처리에서 지상부 생체중이 가장 높았으며, 20/4h, 22/2h 순이었다. 팁번의 발생은 상대습도 60/90%에서는 명/암주기 16/8h로 처리했을 때 1.4%로 매우 낮았으나, 명기 시간이 연장된20/4h, 22/2h 처리에서 각각 15.5% 30.3%로 급격히 증가하였다. 상대습도 60/60%에서는 명/암주기 16/8h에서도 팁번의 발생이 15.5%로 높았으며 20/4h, 22/2h 처리에서는 25% 이상 높게 나왔다. 줄기의 경도는 상대습도 60/90%, 명/암주기 16/8h 처리에서 가장 낮았다. 잎의 무기성분은 명기시간이 연장될수록 감소하였지만 Ca의 함량은 상대습도 60/60%, 명/암주기 22/2h 처리를 제외하고는 유의한 차이가 없었다.

• Membrane and Water Treatment
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• 제10권1호
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• pp.39-44
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• 2019

LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

• The Korean Journal of Ecology
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• 제11권2호
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• pp.65-76
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• 1988

A number of laboratory and field experiments have performed with aqueous extracts from fresh leaves, fallen leaves and roots of Pinus rigida in order to investigae the effetct of the pine tree. The results obtained found its inhibitive effect on the germination and growth of tested species. Though relative germination ratio of the species was somewhat lower than the control plot, severe inhibition was observed in relative dry weight ration, These results were more obvious in aqueous extracts than in the case of leachates and similar results were also confirmed by field bioassays on the forest soil of P. rigida. Therefore, to find out the inhibitory sybstancesm 14 different kinds of KDICical substances were isolatd from the leaved of the tree by chromato-graphy and nist if them were confirmed to be phenoic compounds, The growth of lettuce was inhibition was observed in the concentration of less than 5X10-3M soluton. Phenolic compounds are assumed the substance related to the allelopathic effect of P. rigida.

• 미생물학회지
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• 제15권2호
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• pp.63-76
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• 1977

Irradiation with high doses of gamma rays induced the reduction of mycelial weight and anaylase activity, and increased relative amylase activity in surface cultures. Biphase in growth curves was shown in aeration-agitation cultures but the behavior of the first phase of growth could be eliminated by replacing the amylasehydrolysed starch substrates, so that enzyme production was shortened ca. 40 hours and relative amylase activity was increased about 3 times higher before onset of autolysis. In the effect of gibberellin on amylase production, the positive stimulation was appeared to only surface culturs of the liquid medium and the negative effect to shake-cultures in a mutant. Trials of various continuous culture were resulted not only the approalch to the value of amylase activity in surface cultures of liquid medium, but also higher productivity than in batch cultures. The culture-degeneration was observed in two-stage continuous culture, but did not appear in continuous elevation culture.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.52-53
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• 2001

The dietary effects of conjugated linoleic acid (CLA) on lipid concentrations and fatty acid composition of various tissues were studied in young chicks. Chicks were fed one of four diets containing 6% tallow (TO), 4% TO-2% CLA, 2% TO-4% CLA or 6% CLA for 3wks. There were no differences in growth performances, but relative liver weight in chicks fed dietary CLA up to 4% was significantly higher than that of 6% TO group. The concentrations of various lipid fractions in serum were not affected by CLA feeding. With the increase in dietary CLA levels, total CLA in liver and leg muscle increased linearly.

• Smart Structures and Systems
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• 제15권3호
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• pp.609-625
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• 2015

Management of infrastructure stock is essential in sustainability of society, and its analysis and optimization are studied in the light of control system modeling in this paper. At the first part of the paper, cost of stock management is analyzed based on macroscopic statistics on infrastructure stock and economical growth. Stock management burden relative to economy is observed to become larger at low economic growth periods in developed economies. Then, control system modeling of stock management is introduced and by augmenting maintenance actions as control input, dynamic behavior of stock is simulated and compared with existing time history statistics. Assuming steady state conditions, applicability of the model to cross sectional data is also demonstrated. The proposed model is enhanced so that both preventive and corrective maintenance can be included as system inputs, i.e., feedforward and feedback control inputs. Optimal management strategy to achieve specified deteriorated stock level with minimal cost, expressed in terms of preventive and corrective maintenance actions, is derived based on estimated parameter values for corrosion of steel bridges. Relative cost effectiveness of preventive maintenance is shown when target deteriorated stock level is lower.

• International Journal of Industrial Entomology and Biomaterials
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• 제20권2호
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• pp.69-74
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• 2010

Feeding is an important aspect of insect nutrition which in turn supports growth, development, reproduction and survival. The impact of quantitative feeding on nutritional parameters of fifth instar Antheraea mylitta larvae was studied by providing fresh leaves of Terminalia tomentosa for 1 to 4 times a day. All the parameters improved upon providing fresh diets more times over the single diet (1FD). The absolute body weight increased with increase in number of feeds/day significantly (P<0.001). While the maximum weight recorded was 29.61 g in 1FD, the respective weights for two feeds/day (2FD), three feeds/day (3FD) and four feeds/day (4FD) were 39.41 g, 40.63 g and 42.66 g respectively. Feeding period and instar duration were declined (P<0.001) and survival increased significantly (P<0.001) upon increase in the number of diets. Nutritional indices like ingestion, digestion, relative consumption rate (RCR), relative growth rate (RGR) and gain in body weight increased significantly with the increase in number of feeds/day, but approximate digestibility (AD) and efficiency of conversion of ingested food (ECI) declined, while efficiency of conversion of digested food (ECD) did not change.