• Journal of Biosystems Engineering
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• v.29 no.4
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• pp.347-356
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• 2004

치아인회석, 키토산, 시아노아크릴레이트 등의 생분해성 생체재료를 이용해 새로운 생체흡수성 골시멘트를 개발하고자 하였다. 이들 골시멘트들에 대해서 중합온도, 응고시간 등의 조작특성과 압축강도, 전단강도 등의 물성을 분석하였다. 특히, 치아인회석과 키토산의 미립가루와 부틸 시아노아크릴레이트의 강력접착제를 이용한 시멘트(B)에 대해서는 직접 접촉방법과 XTT 방법을 통해 세포독성을 분석하였고, 또한 쥐를 이용한 동물실험에서 시멘트(B)의 처리그룹에 따라 생체적합성을 분석하였다. 시아노아크릴레이트를 이용한 골시멘트의 최대중합온도는 약 33$^{\circ}C$, 조작(응고)시간은 3-6분, 압축강도는 약 15-25㎫, 전단강도는 약 0.4-l.7 ㎫를 나타내었다. 첨가제로 사용된 Lipiodol은 골시멘트의 주사성과 강력접착제의 초기 중합지연도를 높였고, 특히 송진가루는 시아노아크릴레이트의 초기중합을 지연시켰다. 시아노아크릴레이트를 이용한 시멘트(B)의 세포독성을 분석한 결과, 대부분의 처리 그룹에서 낮게 나타났고, 특히 키토산과 치아인회석을 사용한 경우 각각 세포 독성이 더 낮게 나타났다. 그리고 골시멘트(B)의 동물 생체적합성 실험의 방사선상 및 조직학적 분석에서도 뼈 형성 및 결합이 우수하게 나타났다.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.211-218
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• 1985

To establish the weed control in transplanted bed of Pinus koraiensis and Larix leptolepis, alachlor, simazine, terbutryn, pendimethalin, oxyfluorfen and amitrol/2,4-D/methabenthiazuron (ustinex) were used by soil treatment and foliage application at 7days after transplantion of seedling. From the of soil treatment, grasses such as Dimeria ornithopoda, Alopecurus aequalis, Agropyron tsukushiense and Setaria verticillata were effectively controVed by 85 to 90% at the respective recommended rate of oxyfluorfen, alachlor and terbutryn. At the application rate of recommentation simazine, oxyfluorfen, pendimethalin and terbutryn respectively controlled 70 to 80% of broad-leaved weeds such as Erigeron annuus, Portulaca olearcea, Cerastium arvense, Capsella bursa-pastoris, Commelina commuis, Chenopodium hybridum and Stellaria alsine. Ustinex and oxyfluorfen were very effective for the control of perennials such as Artemisia princeps and Calystegia japonica. Initial sympton of phytotoxicity and decrease of growth in P. koreaiensis and L. leptolepis were not found by soil treatment and those in P. koraiensis was not shown by foliage application of all tested herbicides. But L. leptolepis foliage-applied with ustinex, oxyfluorfen, terbutryn and pendimethalin was great in early phytotoxicity and severe in growth inhibition.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.323-327
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• 2006

This study was conducted to understand response of damage and tolerance to ozone between ozone tolerant and sensitive families of P. densiflora which had been selected by the based on visual injury and growth. Five individuals were selected in each group, and were exposed to 100ppb ozone for 90 days. Every 30 days after ozone fumigation, diamter at root collar (ORC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were measured. In early state of ozone fumigation tolerant families showed three times higher relative DRC growth rate than sensitive families. And during whole fumigation period growth rate of tolerant families was superior to growth rate of sensitive families. SOD activity in sensitive families was increased 30 days after fumigation, and in accordance with fumigation period extended it was decreased continuously. MDA content in ozone treatment showed higher than in control, and MDA content of tolerant families was higher than that sensitive families. In our results tolerant families has higher antioxidative activity than sensitive families. Therefore tolerant families can restrain lipid peroxidation and damage on physiological activity.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.106-115
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• 1998

This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.146-151
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• 1990

The viability of rhizobia according to various kinds of carrier materials, inoculum size, storage temperature and sterilization methods was investigated for the development of legume inoculat. The results were followings. 1. Peat and perlite were favorable as a carrier material. 2. Rhizobia counts were reached to $5{\times}10^8cells/g$ carrier 1-2 weeks after inoculation with inoculum size below $10^4cells/g$ carrier. 3. $10^9cells/g$ carrier was maintained 12 weeks after storage at room temperature. 4. Steam heat sterilization was the best method for carrier sterilization among methods used in this study. Dry heat and ${\gamma}$-ray sterilization were also applicable.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.3010-3023
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• 1998

GA has a fast convergence speed in searching the one point around optimal value. But it's convergence time increase in searching the region around optimal value because it has no regional searching mechanism. BP has the tendency to converge the local minimum because it has global searching mechanism. To overcome these problems, a method in which a genetic algorithm and a back propagation are applied in turn is proposed in this paper. By using a genetic algorithm, we compute optimal synaptic strength and offset value. And then, these values are fed to the input of the back propagation. This proposed method is superior to each above method in improving the convergence speed.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.235-240
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• 2002

Protease producing bacterium, PB16 was isolated from food processing wastewater sludge and paddy field soil samples and selected by the clear zone and enzyme activity test. The isolate was gram negative, rod type and its protease productivity was 6.49 U/ml. As a result of API20NE kit test and 16S rDNA sequencying, the isolated PB16 was identified as Aeromonas hydrophila (99%). The growth rate ($h^{-1}$) was 0.21 in synthetic waste water only and 0.26 in synthetic waste water containing vitamin and mineral using a bioscreen C. Synthetic wastewater removal rate was 59 and 87%, respectively after 1 and 3 day reaction (intial CODcr was 2,472 mg/l).

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.1-8
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• 2010

Noise removal methods for noisy images have been studied a lot in the domain of spatial and transform filtering. Low pass filtering was initially applied in the spatial domain. Recently, discrete wavelet transform has widely used for image denoising as well as image compression due to an excellent energy compaction and a property of multiresolution. In this paper, Gabor cosine and sine transform which is considered as human visual filter is applied to image denoising areas using soft thresholding technique. GCST is compared with excellent wavelet transform which uses existing soft thresholding methods from PSNR point of view. Resultant images removed noises are also visually compared. Experimental results with adding four different standard deviation levels of Gaussian distributed noises to real images show that the proposed transform has better PSNR performance of a maximum of 1.18 dB and visible perception than wavelet transform.

• KSBB Journal
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• v.18 no.6
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• pp.461-465
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• 2003

Five denitrifying bacteria, which were identified as Pseudomonas sp., were isolated by the enrichment culture technique. The most effective denitrifying bacterium was named as Pseudomonas DWS, which was cultivated at anoxic condition. The optimal growth temperature and pH were 30$^{\circ}C$ and 7-8, respectively. Cell growth almost revealed a stationary phase at 18 hours after cultivation and nitrate was degrade 99.9％ during this period. Therefore, it is suggested that Pseudomonas DWS could be effectively used for the biological treatment of wastewater containing nitrogen compounds.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.77-88
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• 2015

In this paper, we consider a two-agent single-machine scheduling problem with exponential job-dependent position-based learning effects. The objective is to minimize the total weighted completion time of one agent with the restriction that the makespan of the other agent cannot exceed an upper bound. First, we propose a branch-and-bound algorithm by developing some dominance /feasibility properties and a lower bound to find an optimal solution. Second, we design an efficient simulated annealing (SA) algorithm to search a near optimal solution by considering six different SAs to generate initial solutions. We show the performance superiority of the suggested SA using a numerical experiment. Specifically, we verify that there is no significant difference in the performance of %errors between different considered SAs using the paired t-test. Furthermore, we testify that random generation method is better than the others for agent A, whereas the initial solution method for agent B did not affect the performance of %errors.