• The Korean Journal of Mycology
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• v.50 no.4
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• pp.367-372
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• 2022

Leaf spot symptoms were observed in water spinach (Ipomoea aquatica) plants growing in fields in Ansan and Hongseong, Korea, during disease surveys in 2019 and 2020. The symptoms appeared as brown to dark brown circular or irregular spots on the leaves of the plants. The disease incidence on the plant leaves in the fields investigated at the two locations ranged from 1% to 20%. Five single-spore isolates of Phoma sp. Were obtained from lesions of the diseased leaves. All the isolates were identified as Ectophoma multirostrata based on their cultural and morphological characteristics, as well as molecular analysis. Two isolates of E. multirostrata were tested for pathogenicity on water spinach leaves using artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants. These symptoms were similar to those observed in plants from the investigated fields. To our knowledge, this is the first report of E. multirostrata causing leaf spot in water spinach.

• The Korean Journal of Mycology
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• v.50 no.1
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• pp.61-64
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• 2022

In July and September 2020, a severe outbreak of stem rot was observed on bonnet bellflower (Codonopsis lanceolata) plants in a farm located in Chuncheon, Gangwon Province, Korea. The symptoms initially appeared on the stem at or above the soil line. Later, the infected stem completely rotted and blighted. The incidence of diseased plants in the field was 2-30%. Ten isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-4 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-4 were tested for pathogenicity on bonnet bellflower plants through artificial inoculation. All tested isolates induced stem rot symptoms on the inoculated plants. The symptoms were similar to those observed in plants from the farm. This is the first report of R. solani AG-4 causing stem rot in bonnet bellflower.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.357-360
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• 2022

In July 2021, we surveyed diseases affecting wild vegetables grown in Hongcheon, Gangwon Province, Korea. During this survey, we observed severe seedling rot symptoms in Kamchatka goatsbeard (Aruncus dioicus) grown in a vinyl greenhouse. The incidence of the disease in the plant seedlings was 1-10%. Diseased seedlings from this population were collected, and fungi were isolated from leaf and petiole lesions. Rhizoctonia sp. was consistently isolated from the lesions. We examined the morphological and cultural characteristics and anastomosis groups of nine Rhizoctonia sp. isolates obtained from the lesions. The results revealed that all isolates corresponded to Rhizoctonia solani AG-1(IB). Three isolates of R. solani AG-1( IB) were evaluated to determine their pathogenicity towards Kamchatka goatsbeard seedlings through artificial inoculation. The tested isolates caused rot symptoms on the inoculated plant seedlings. The symptoms were similar to those observed in plant seedlings from the vinyl greenhouse. We found that R. solani AG-1(IB) caused seedling rot of Kamchatka goatsbeard.

• The Korean Journal of Mycology
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• v.51 no.1
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• pp.63-68
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• 2023

From June to August 2021, we surveyed diseases affecting beet (Beta vulgaris subsp. vulgaris) plants in Cheolwon, Hoengseong, and Pyeongchang regions in Gangwon Province, Korea. We observed severe leaf spot symptoms, such as brown to dark circular or irregular spots on the leaves, in plants. Disease incidence in the plant leaves in the fields investigated at the three locations ranged from 1 to 80%. Five single-spore isolates of Phoma sp. were obtained from the diseased leaves and identified as Neocamarosporium betae based on their cultural, morphological, and molecular characteristics. Three isolates of N. betae were subsequently tested to confirm their pathogenicity in beet plants via artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants, similar to those observed in the plants in the investigated fields. Therefore, our findings revealed N. betae as the pathogen causing beet leaf spot in Korea.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.287-288
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• 2020

본 논문에서는 휠체어 이용자들에게 서울 여행 시 필요한 정보를 제공하는 시스템을 구현한다. 이 시스템은 휠체어 이용 시 용이한 대중교통인 지하철역의 편의시설 및 서울 여행지들에 존재하는 부가시설들의 위치에 대한 정보를 제공한다. 방대한 여행정보가 제공되는 상황에서도 상대적으로 이를 누리지 못하는 장애인들에게 본 논문은 여행 및 이동에 필요한 정보를 제공할 수 있다는 특징을 가지고 있다.

• Journal of Information Processing Systems
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• v.19 no.3
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• pp.275-288
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• 2023

Many image edge details are easily lost in the image denoising process, and the smooth image regions are prone to produce jagged. In this paper, we propose a wavelet-based image global k- singular value decomposition variational method to remove image noise. A layer of wavelet decomposition is applied to the noisy image first. Then, the image global k-singular value decomposition (IGK-SVD) method is used to remove the random noise of low-frequency components. Furthermore, a constructed variational denoising method (VDM) removes the random noise in the high-frequency component. Finally, the denoised image is obtained by wavelet reconstruction. The experimental results show that the proposed method's peak signal-to-noise ratio (PSNR) value is higher than other methods, and its structural similarity (SSIM) value is closer to one, indicating that the proposed method can effectively suppress image noise while retaining more image edge details. The denoised image has better denoising effects.

• Journal of applied mathematics & informatics
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• v.41 no.4
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• pp.893-906
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• 2023

In this article, we are devoted to study the problem of the existence, uniqueness and positivity of the global solutions of the 3 × 3 reaction-diffusion systems with the total mass of the components with time. We also suppose that the nonlinear reaction term has a critical growth with respect to the gradient. The technique that we used to prove the global existence is the method of the compact semigroup.

• Research in Plant Disease
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• v.29 no.2
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• pp.184-187
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• 2023

In May 2020, we surveyed disease occurrence on vegetables grown in Seosan area, Korea. During the disease survey, white rot symptoms were observed in Korean wild chive (Allium monanthum) plants growing in fields. The symptoms occurred mainly in the seed bulb-producing fields of the crop. The above ground parts of the diseased plants displayed premature yellowing and dying of older leaves and stunting of the plants. The bulbs and roots of the diseased plants turned black and rotted. The disease occurred in a range of 1-60% in four of the eight fields surveyed. Three isolates of Sclerotium sp. were obtained from the bulb lesions of diseased plants. All isolates were identified as Stromatinia cepivora based on the morphological characteristics and phylogenetic analysis. Pathogenicity of the isolates on Korean wild chive was confirmed by artificial inoculation test. The lesions induced by the inoculation test were similar to those observed in the investigated fields. This is the first report of S. cepivora causing white rot in Korean wild chive.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.7-8
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• 2022

본 연구에서는 한국어 SNS 대화에서 나타나는 문장들의 감성을 분석하고자 신경망 모델을 활용하여 시스템을 구축하였다. 현재 해외 SNS 감성분석에 대한 연구는 많이 진행된 상황이지만, 한국어 범용 대화에 대해 적절한 모델이 무엇인지는 연구가 부족한 실정이었다. 따라서 한국어 대화에 적합한 모델을 채택해 보다 정확한 감성분석을 수행하였다. 이를 위해 한국어 SNS 대화 데이터에 대해 신경망 모델을 적용하여, 82% 성공률로 기존 모델 72% 성공률보다 훨씬 더 우수한 성능을 보였다. 또한 본 연구의 결과는 악플 추적 등 실용적인 분야에도 기여할 수 있다고 사료된다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.11-12
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• 2022

이 연구는 대기오염과 미세먼지의 각 성분이 질환에 미치는 영향에 대한 데이터만 존재한다면 어떠한 질환이든 위험도 예측 결과를 알 수 있는 것에 의미가 있다. 또한 기존의 대기정보에 따른 정보를 예상하는데 필요한 데이터 종류와 수가 많았으며 계산의 복잡성이 높았고 정보의 제공 범위가 넓었다. 하지만 이 연구는 과거 대기 데이터와 딥러닝을 통해서 낮은 비용으로 더욱 자세하게 유해질환 위험도를 예측하는 시스템을 구축하였다. 이 연구에서 구축한 시스템은 예측 결과 88.9%의 정확도를 보였다. 이 시스템은 입력되는 데이터의 정보에 따라 세분화된 지역의 대기환경 정보 또한 파악 가능하며 그 과정이 매우 간편하고 유용하다. 이 시스템은 공기질 예측을 위해 유용하게 사용될 수 있을 것이라고 사료된다.