• 제목/요약/키워드: Regeneration rate

검색결과 704건 처리시간 0.048초

ATM 망에서의 셀 손실 복구 기법에 관한 연구 (Cell Loss Recovery Algorithm for ATM Networks)

  • 심윤섭;천상훈;곽경섭
    • 전기전자학회논문지
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    • 제3권1호
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    • pp.22-28
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    • 1999
  • 기존의 CREG-VP는 VP상에서 FEC기법을 사용하여 트래픽 과잉으로 인한 연속적인 셀 손실을 보상하는 기법으로써, 평균 코딩/디코딩 시간이 짧고, ATM 표준 셀 형식과 호환성을 유지할 수 있다는 장점을 지니고 있으나, 복구할 수 있는 셀의 수에는 제한이 존재한다. 본 논문에서는 CREG-VP를 확장하여 버스트 특성을 갖는 트래픽에서도 효과적으로 셀 손실을 복구하는 기법을 제안하였다. 제안된 기법은 CRP를 변경하여 셀 손실의 검출 성능을 향상시켰고, 인터리브 패리티 셀을 적용하여 연속적인 셀의 복구성능을 향상시켰다. 실험 결과 제안된 기법은 CREG-VP 방식보다 셀 손실률 감소 계수를 향상 시킴을 알 수 있었다.

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흰쥐에서 반회후두신경 손상 후 만성적 전기자극이 후두 기능 회복에 미치는 영향 (Effects of Chronic Electrical Stimulation on Functional Recovery Following Laryngeal Reinnervation in the Rat)

  • 김지연;조선희;한후재;박수경;신유리;정성민
    • 대한후두음성언어의학회지
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    • 제11권2호
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    • pp.172-177
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    • 2000
  • Background and Objectives : Until now, various attempts have been made fir reinnervating paralyzed vocal cord. Nevertheless, the most cases did not produce satisfactory outcome due to occurrence of synkinesis of larynx secondary to misdirected axonal regeneration. Accordingly, the purpose of this investigation is to learn the effect of chronic electrical stimulation on regeneration of the recurrent laryngeal nerve. Material and Methods : Using 20 healthy male Sprague-Dawley rats(250-300g) with normal vocal functions, transections were made on their left recurrent laryngeal nerves and then primary anastomosis were performed under the operating microscope and they were divided into an experimental group and a control group each having 10 rats. After the procedure, for the experimental group, chronic electrical stimulation was carried out until vocal cord movement was functionally recovered. for the control group, only chronic electrical stimulation was not given. Result : In experimental group, the number of functionally recovered rats was two and in control group, that of functionally recovered rate was same. The reorganization of posterior cricoarytenoid muscle motoneuron in nucleus ambiguus appeared in the case of directed reinnervation of recurrent laryngeal nerve. Conclusion : The chronic electrical stimulation does not a direct beneficial effect on the early functional recovery in rats with injured recurrent laryngeal nerve.

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An Improved Method of Organogenesis from Cotyledon Callus of Acacia sinuata (Lour.) Merr. using Thidiazuron

  • Shahzad Anwar;Ahmad Naseem;Anis Mohammad
    • Journal of Plant Biotechnology
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    • 제8권1호
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    • pp.15-19
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    • 2006
  • An efficient protocol for in vitro multiple shoot bud induction and plant regeneration from mature green cotyledon derived callus tissues of Acacia sinuata has been developed. Callus formation occurs at all the concentrations of thidiazuron (TDZ) in Murashige and Skoog's (MS) medium, but 0.6 ${\mu}M$ proved to be the best with maximum callus formation frequency. Supplementation of TDZ in combination with indole-acetic acid (IAA) in MS media accelerates shoot bud organogenesis in differentiating callus tissues with 60-70% conversion of shoot buds into shoot Most efficient shoot organogenesis was recorded when TDZ induced calli were subcultured at different concentrations of 6-benzyla-denine (BA). Optimum shoot bud induction and plant regeneration from callus was achieved when 0.6 ${\mu}M$ (TDZ) induced calli were subcultured at 3.0 ${\mu}M$ (BA) where $16.6{\pm}0.74$ shoots/unit callus on obtained. Rooting in in vitro differentiated shoots was achieved when transferred to medium containing different concentration of indole-3-butyric acid (IBA) in full & half strength MS medium. The well rooted plantlets were hardened and transferred to net house with 90% survival rate.

A Study on the Use of Empty Stores to Prevent Gentrification in Commercial Regeneration

  • RYU, Tae-Chang
    • 유통과학연구
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    • 제17권6호
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    • pp.43-56
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    • 2019
  • Purpose - With the increasing number of small business owners who reports the cessation of their businesses, the rate of closing the business within the year is increasing as well. The efforts have been made continuously to revitalize the business through the inflow of government or private capital. Maintaining the fast-changing commercial districts with the existing support is difficult, so it is urgent state that needs for commercial district reorganization. The differentiate aspect is that this new measures for small-block-unit commercial modeling can be introduced to promote these aging/deposit private-owned shops politically. Research design, data, and methodology - This study is to develop a sustainable theme shopping rehabilitation method which considers the characteristics of local cities based on the case studies of developed countries' commercial areas to revitalize the central urban areas of local cities. Results - The purpose of this study as stated above is to manage the local commercial area through the program that purchases the empty stores, and the measure to secure the autonomy among stores. Conclusions - The government should concentrate on projects such as vacant store purchase programs, which are omitted from past achievements, and maximize the effect of the project through inter-departmental project packages.

Effect of Neurotrophic Factors on Neuronal Stem Cell Death

  • KimKwon, Yun-Hee
    • BMB Reports
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    • 제35권1호
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    • pp.87-93
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    • 2002
  • Neural cell survival is an essential concern in the aging brain and many diseases of the central nervous system. Neural transplantation of the stem cells are already applied to clinical trials for many degenerative neurological diseases, including Huntington's disease, Parkinson's disease, and strokes. A critical problem of the neural transplantation is how to reduce their apoptosis and improve cell survival. Neurotrophic factors generally contribute as extrinsic cues to promote cell survival of specific neurons in the developing mammalian brains, but the survival factor for neural stem cell is poorly defined. To understand the mechanism controlling stem cell death and improve cell survival of the transplanted stem cells, we investigated the effect of plausible neurotrophic factors on stem cell survival. The neural stem cell, HiB5, when treated with PDGF prior to transplantation, survived better than cells without PDGF. The resulting survival rate was two fold for four weeks and up to three fold for twelve weeks. When transplanted into dorsal hippocampus, they migrated along hippocampal alveus and integrated into pyramidal cell layers and dentate granule cell layers in an inside out sequence, which is perhaps the endogenous pathway that is similar to that in embryonic neurogenesis. Promotion of the long term-survival and differentiation of the transplanted neural precursors by PDGF may facilitate regeneration in the aging adult brain and probably in the injury sites of the brain.

Shoot Proliferation of Populus euramericana(Populus deltoides X P. nigra) through in vitro Tissue Culture

  • Kang, Ho-Duck;Moon, Heung-Kyu
    • Plant Resources
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    • 제4권3호
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    • pp.111-120
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    • 2001
  • The efficiency of in vitro regeneration of four clones of Populus euramericana, Canada blanc, Eugenii, I-45/51, and Wisconsin #5, was examined. Cytokinins and the combinations with auxins affected the rate of regeneration from the explants of root segments, stem internodes, and leaf discs. Overall, BA and the combination with auxins were effective in root segments and leaf discs of the Canada blanc clone, whereas zeatin and the combination with auxins were important in stem internodes of the Wisconsin #5 clone. The highest number of shoots averaging 17.6 $\pm$ 0.47 from root segments in the Canada blanc clone,18.2 $\pm$ 3.0 from stem internodes in the Wisconsin #5 clone, and 17.8 $\pm$ 1.92 from leaf discs in the Canada blanc clone were obtained with 2.0 mg/1 BA, 2.0 mg/l zeatin combined with 0.2 mg/l IAA, and 0.5 mg/l BA combined with 0.05 mg/l 2,4-D, respectively. In particular, the addition of 2,4-D into cytokinin medium promoted shoot proliferation.

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Alteration of Gas Exchange in Rice Leaves Infected with Magnaporthe grisea

  • Yun, Sung-Chul;Kim, Pan-Gi;Park, Eun-Woo
    • The Plant Pathology Journal
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    • 제16권5호
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    • pp.257-263
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    • 2000
  • Infection with rice blast fungus (Magnaporthe grisea) significantly reduced foliar net photosynthesis (A) of rice cultivars: Ilpoom, Hwasung, and Choochung in greenhouse experiments. By measuring the amount of diseased leaf area with a computer image analysis system, the relation between disease severity (DS) and net photosynthetic rate was curvilinearly correlated (r=0.679). Diseased leaves with 35% blast symptom can be predicted to have a 50% reduction of photosynthesis. The disease severity was linearly correlated (r=0.478) with total chlorophyll (chlorophyll a and chlorophyll b) per unit leaf area(TC). Light use efficiency was reduced by the fungal infection according to the light response curves. However, dark respiration (Rd) did not change after the fungal infection (p=0.526). Since the percent of reduction in photosynthesis greatly exceeded the percent of leaf area covered by blast lesions, loss of photosynthetic tissue on an area basis could not by itself account for the reduced photosynthesis. Quantitative photosynthetic reduction can be partially explained by decreasing TC, but cannot be explained by decreasing Rd. By photosynthesis (A)-internal CO$_2$ concentration (C$_i$ curve analysis, it was suggested that the fungal infection reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, ribulose-1,5-bisphosphate (RuBP) regeneration, and inorganic phosphate regeneration. Thus, the reduction of photosynthesis by blast infection was associated with decreased TC and biochemical capacity, which comprises all carbon metabolism after CO$_2$ enters through the stomata.

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소형디젤엔진용 전기히터방식 매연여과장치의 재생특성 향상을 위한 흡기드로틀링 적용연구 (Application of Intake Throttling for Improving Regeneration Characteristics of an Electrical Heated DPE System)

  • 김홍석;한승한;김진현;조규백;정용일;황재원;한상명
    • 한국자동차공학회논문집
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    • 제13권6호
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    • pp.77-83
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    • 2005
  • Application of an electric heater is one of attractive methods for active regeneration in DPF systems, but its application has been limited by the capacity of electric power available in vehicles. This study was focused on intake throttling to reduce electrical energy required in the electrical heated DPF system. As results, this study showed the decrease of $30\~50\%$ of intake air mass flow rate and the increase of $20\~60^{\circ}C$ of exhaust gas temperature by the proper control of intake throttling. These intake throttling effects was helpful for regenerable temperature achievement.

Factors Affecting on Regeneration in 'WHANGKEUMBAE' Pear (Pyrus pyrifolia)

  • Lee, Gung-Pyo
    • 농업생명과학연구
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    • 제43권6호
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    • pp.59-65
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    • 2009
  • Combinations of plant growth regulators, darkness treatments, and the order of expanding leaves for explants were evaluated for optimizing in vitro shoot regeneration rate of 'Whangkeumbae' pear. In a MS medium, supplemented with $8.88{\mu}M$ 6-benzylaminopurine (BA) and $0.49{\mu}M$ indole-3-butyric acid (IBA), green foci were observed on the surface of the callus 8 days after culture initiation. Some adventitious buds were later induced from those green foci, resulting in the appearance of normal shoots. In a medium containing $22.20{\mu}M\;BA$, the surface of the callus became compact and greenish, and many adventitious buds were formed over the entire area of the callus surface. When comparing BA concentration via histological observation, the section which had been treated with $22.20{\mu}M\;BA$ exhibited closer cell aggregation than those with $8.88{\mu}M\;BA$. The darkness treatment enhanced the formation of adventitious shoots for up to 3 weeks. The youngest two expanding leaves, proximal to the shoot apex, were proved to be the most regenerative, and yielded the highest shoot number per regenerating leaf. A fourth strength MS medium, which was supplemented with $0.54{\mu}M\;NAA$, yielded good quality plantlets, with regard to root number and root length.

인쇄업에서 배출되는 반응성 VOCs 종류와 흡착 제거 방법의 적용 (Volatile organic compounds emitted from printing processes and their removal by adsorption)

  • 안해영;이윤경;송지현
    • 실내환경 및 냄새 학회지
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    • 제17권4호
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    • pp.396-403
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    • 2018
  • In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.