• Research in Plant Disease
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• v.28 no.3
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• pp.152-161
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• 2022

Several types of chemical bactericides have been used to control fire blight. However, their excessive usage leads to environmental deterioration. Therefore, several researchers have analyzed antagonistic microorganisms as promising, effective, and safe biological control agents (BCAs). The primary aim of this study was to screen for potential antagonistic bacteria that suppress Erwinia amylovora. Among the 45 isolates studied, 5 strains showed the largest inhibition zone against E. amylovora. 16S rRNA gene sequencing identified them as Bacillus amyloliquefaciens (KPB 15), B. stratosphericus (KPB 21), B. altitudinis (KPB 25), B. safensis (KPB 31), and B. subtilis (KPB 39). KPB 25 and 31 reduced the lesion size of fire blight by 50% in immature apple fruits, and did not show antagonism against each other. Therefore, KPB 25 and 31 were selected to develop an antagonistic mixture against fire blight. Although the mixture with KPB 25 and 31 showed a slightly increased ability to reduce lesion size on immature fruits, they did not exhibit a synergistic effect in reducing E. amylovora population compared to each strain alone. Nevertheless, we have identified these two strains as useful and novel BCAs against fire blight with additional benefits safety and potential in developing a mixture without loss of their activity, owing to the absence of antagonism against each other.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.325-331
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• 2009

Three beneficial bacterial agents, Lactobacillus strain KLF01, Lactococcus strain KLC02 and Paenibacillus strain KPB3 were showed clear zone against plated Pectobacterium carotovorum subsp. carotovorum (Pcc) soft rot pathogen. In greenhouse test, bio-control efficacy was more significantly effective in the treatments by KLC02 and KPB3 as 64%, 50%, 56% and 66%, 57%, 58% according to date of evaluation, respectively. In case of KLF01 control effect was relatively lower than treatments of KLC02 and KPB3 but its efficacy was still significantly observed when compared to control (only water treatment). Furthermore, KLF01, KLC02 and KPB3 showed 55%, 60% and 62% bio-control efficacy, respectively in field test from early March to late July of 2009. Thus, we suggest that these strains can be useful as bio-control agents against soft rot caused by Pcc.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.313-319
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• 2006

Two hundred bacterial strains were isolated from the soil around healthy tomato plants in a polyvinyl house, where most of the other plants showed bacterial wilt symptoms. The strains were screened in vitro for their antibacterial activity. Among them, a strain, KPB3 showed strong bactericidal activity against bacterial wilt pathogen, Ralstonia solanacearum. The strain KPB3 was identified using physiological and biochemical tests, and 16S rRNA analyses. Based on these tests, the strain was found to be closer to genus Paenibacillus. To control the bacterial wilt caused by R. solanacearum, greenhouse experiments were conducted to determine the effectiveness of the Paenibacillus strain KPB3. Drench application of this strain ($4{\times}10^8$ CFU $mL^{-1}$) into the pots containing tomato plants, post-inoculated with the pathogen, R. solanacearum could drastically reduce the disease severity, compared to the non-treated plants. To evaluate effectiveness of this strain under field conditions, experiments were carried out in polyvinyl houses infested with R. solanacearum, during spring and autumn of the year 2006. It was observed that, during spring, bacterial wilt was more prevalent compared to the autumn. During spring, 50.9% disease incidences occurred in non-treated controls, while, Paenibacillus strain KPB3 treated plants showed 24.6% disease incidences. Similarly, during autumn, around 17.2% plants were infected with bacterial wilt in non- treated polyvinyl houses, compared to the Paenibacillus strain KPB3 treated plants, which showed 7.0% disease incidences. These results demonstrated that, Paenibacillus strain KPB3 is a potential biological control agent against bacterial wilt caused by R. solanacearum, effective under greenhouse as well as field conditions. This is the first report showing biocontrol of R. solanacearum using a Paenibacillus spp. under field conditions.

• Korean Journal of Pharmacognosy
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• v.37 no.3
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• pp.184-189
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• 2006

To find the monthly variation of kalopanaxsaponin contents in the leaves of Kalopanax pictus with thorns (KPT) and with no thorns (KPN), the leaves monthly collected from May to September were extracted with MeOH and then the kalopanaksaponin fractions were prepared. KPT collected on May showed the lowest saponin content of the KPTs whereas KPT on August exhibited the highest saponin content. From September, the saponin content in the loaves decreased. The highest saponin content was shown to be 7.3% in KPN collected on August. Evaluation of six kalopanaxsaponins A, I, J, B, H and K (KPA, KPI, KPJ, KPB, KPH, and KPK) were performed using TLC densitometer. In this measurement, considerably higher KPB and KPH, both hederagenin bisdesmosides, were found whereas very low contents In monodesrnosides KPI and KPJ were observed. In conclusion, it was shown that the leaves of KPN of August could be a biomaterial source for the kalopanaxsaponin fraction. It was also suggested that measurement of the weight of kalopanaxsaponin fraction and the content of KPB as the representative compound for kalopanaxsaponins will be used for the quantitative evaluation of the kalopanaxsaponins of K. pictus.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.73-76
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• 2002

본 논문에서는 8kbps의 전송율을 가진 ITU G.729 보코더와 PSOLA(Pitch Synchronized Overlap -Add) 알고리즘을 적용하여 전송율을 6kbps와 4kbp까지 낮출 수 있는 가변 전송율 보코더를 구현하였다. 제안한 방법은 4kbps일 경우에 G.729의 부호화전에 PSOLA를 적용하여 피치의 주기를 반으로 줄여 부호화한다. 이렇게 부호화된 데이터는 G.729의 복호화를 거치고 다시 PSOLA를 통해 음성의 피치 주기를 2배로 늘려주어 원음성을 합성하게된다. 기존의 Bkbp의 전송율을 갖는 G.729는 음성의 크기가 반으로 줄어 부호화되므로 전송율이 4kpb로 줄어들게 된다. 실험의 평가는 MOS 테스트를 통해 수행되었으며 4kbp에서 MOS값이 3.37정도로 측정되었다. 또한 처리해야할 음성의 길이가 줄어들게 되므로 계산시간도 줄어들게 된다.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.473-485
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• 2019

Kiwifruit (Actinidia spp.) is an economically important crop and a bacterial canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa), is the most destructive disease in kiwifruit production. Therefore, prevent and control of the disease is a critical issue in kiwifruit industry worldwide. Unfortunately, there is no reliable control methods have been developed. Recently, interest in disease control using microbial agents is growing. However, kiwifruit microbiota and their roles in the disease control is mainly remaining unknown. In this study, we secured bacterial libraries from kiwifruit ecospheres (rhizosphere, endospere, and phyllosphere) and screened reliable biocontrol strains against Psa. As the results, Streptomyces racemochromogenes W1SF4, Streptomyces sp. W3SF9 and S. parvulus KPB2 were selected as anti-Psa agents from the libraries. The strains showed forcible antibacterial activity as well as exceptional colonization ability on rhizosphere or phyllosphere of kiwifruit. Genome analyses of the strains suggested that the strains may produce several anti-Psa secondary metabolites. Our results will contribute to develop biocontrol strains against the kiwifruit canker pathogen and the disease management strategies.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.379-388
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• 2014

This study analyzed the status of Korean professional baseball as TV contents utilizing ratings. For the purpose of the study, Korea professional baseball's relative status to other genres though ratings is investigated. For this study, ratings per minute for the whole cable TV channel viewer ratings in 2010 were analyzed, and the following is the result of comparing and analyzing ratings per genre and channel of cable TV. Among 11 genres, drama showed the highest rating, and entertainment, movies, kids, news/reports, sports, music, etc followed. Drama and entertaining channels showed the highest ratings and sports did not show any high ranking. However, when analyzing times for broadcasting Korean professional baseball separately, Korean professional baseball in both genre and channel showed the highest r ratings and it was significant statistically. Thus, it is considered that Korean professional baseball is the most valuable contents for the related cable TV times.