The secondary growth model for Salmonella was developed based on the artificial neural network (ANN) with data collected from ComBase and FoodData Central. In addition to the existing secondary model variables (temperature, pH, Na+, and water contents), more input variables (sugar, carbohydrate, lipid, and protein contents) were considered. The output variables were microbial growth parameters (lag phase duration [l] and maximum growth rate [mmax]). A commercial ANN program (NeuralWorks Predict) was utilized with training at 80%, validation at 10%, and test data at 10%. ANN models were created using all data and cleansed data. Using the cleansed data, the training/testing root mean square error (RMSE) for mmax improved from 0.14/0.16 to 0.11/0.14, whereas the RMSE for l was still not acceptable, from 11.94/33.03 to 7.09/4.18. The l data were divided into two ranges with high and low goodness of fit, whereas the ANN model for each field was built, resulting in an optimally low RMSE.

마늘은 백합과 알리움속에 속하는 영양체작물로 누대재배시 수확량이 감소하는 특성을 보인다. 마늘의 화경 끝에는 주아가 생성되는데, 주아를 파종하여 2년이상 누대재배시 수확량이 약 15% 이상 증가하기 때문에 주아재 배를 통한 종구 갱신이 필요하다. 마늘 주아를 수확 후 저장시 파총채벌레, 파좀나방 등이 발생하며, 저장 중 주아 는 매년 평균 20% 이상의 부패한다. 주아재배를 원활히 하기 위해 주아 저장 시 해충의 방제를 통해 부패율을 줄이는 것이 중요하다. 본 연구에서 주아에서의 해충 발생밀도 및 방제방법에 대한 연구를 진행하였다. 연구결과 주아에서 파총채벌레는 7월 3주차, 파좀나방은 7월 2주차에 각각 발생최성기를 보였으며, 약제 침지시 방제가가 90% 이상 관찰되었다. 약제 침지된 주아 파종시 약해는 발생하지 않아, 주아 해충 방제시 침지법을 활용하여 해충의 밀도를 조절 할 수 있을 것으로 판단된다.

마늘은 백합과 알리움속에 속하는 작물로 약용, 양념채소로 많이 소비되어져 왔다. 마늘은 6월에 수확하여 1개월 간의 건조과정을 거치게 되는데 보통 장마기와 겹치게 되어 연평균 부패율은 5%이상으로 높다. 마늘의 저장중 병해충은 뿌리응애, 마늘혹응애, 마른썩음병 등으로 섭식에 따른 부패를 유발하며, 건조시기를 단축하고 효율적인 건조를 통하여 감모율을 줄이는 것이 중요하다. 마늘의 병해충 피해를 줄이기 위해 개발한 열풍 흡기식 건조장치를 포함하여 관행, 열풍 건조기, 흡기식 건조 등 4가지 방법으로 마늘을 건조하였으며, 방법별 건조소요 일수, 부패율 등을 조사하였다. 연구결과 열풍-흡기식 건조장치의 순환 공기의 온습도는 외기대비 7.8℃ 높았고, 28.6% 낮았으며, 건조 소요일수는 관행건조 대비 31% 수준으로 우수하였다. 또한 병해충 피해 양상은 관행 건조 대비 4.4%p낮아 건조 기간 및 정상품율이 관행 대비 우수하여, 관행 건조를 대체 가능할 것으로 생각된다.

We investigated the effect of habitat environment and colony characteristics on floral bud development in Rhododendron brachycarpum native to Ulleung Island of Korea. Two habitats were considered. Habitat B had a remarkably higher altitude and steeper slope than habitat A. Therefore, fewer types of trees existed on the upper layers, and the density was low. Hence, the degree of light transmission within the community was higher in habitat B. Additionally, flowering ratio of shoots was higher in habitat B, and the amount of light was also relatively higher. The lower the amount of light, lesser the floral development, the higher the leaf area and the specific leaf area, lower the dry weight and chlorophyll content. The total carbohydrate (T-C) and nitrogen (T-N) in shoots are more important than the relative T-C and T-N ratios per leaf. Finally, this study revealed that the floral bud development and flowering of native rhododendrons are strongly associated with the degree of assimilate accumulation in shoots, and that sufficient assimilate accumulation in shoots is essential for stable flowering.

Valves are one of the indispensable components in modern industry. Filling and de-pressure connectors in rocket valves used for space launch vehicles are very important parts for smooth fluid supply. For this reason, an optimized design that can improve efficiency, miniaturization, weight reduction, and safety of the valve at the same time is required. In this work, flow analysis and structural analysis were performed through 3D modeling using computational numerical analysis for open type filling and de-pressure valves. As results, the flow velocity and pressure distribution of the fluid were analyzed through the flow analysis of valve, and stress distribution was conducted in structural analysis. Through this study, it is consequently expected to provide valves of various specifications by performing production and performance test evaluation of development prototypes.

Frankliniella occidentalis is a major pest in agriculture. Following overuse of insecticides, high resistance has developed due to its high reproduction rate and short generation time. To control the resistant strains of the thrips, the ingestion RNAi- based control was established. A total of 67 genes were selected, and their double-stranded RNAs (dsRNA) were delivered to thrips via the leaf disc-feeding method. Among the genes screened, the dsRNA of Toll-like receptor 6 (TLR6) and coatomer protein subunit epsilon (COPE) resulted in the highest mortality (3.8- and 2.8-fold faster LT50 compared to control, respectively) when ingested by thrips. The dsRNA-fed thrips showed 53% and 83% reduced transcription levels of TLR6 and COPE, respectively. This result demonstrates that the observed mortality of thrips following dsRNA ingestion was due to RNAi, and this lethal genes can be employed as a practical tool to control thrips in the field.

Four new species of the genus Alloclubionoides collected from mountain litter and hillock litter around the agricultural ecosystem of Korea are described in the present work with appropriate body measurements and morphological illustrations; A. hwaseongensis sp. nov., A. imi sp. nov., A. namhansanensis sp. nov. and A. nasuta sp. nov. Females of A. hwaseongensis sp. nov., A. namhansanensis sp. nov. and A. nasuta sp. nov. can be distinguished based on the epigyne shape and structure of internal genitalia from previously described species. Males of A. imi sp. nov. can also be distinguished based on the shapes of retrolateral tibial apophysis, embolus tip and conductor from previously described species. Also, a key to the Korean Alloclubionoides spiders is provided. Alloclubionoides gajiensis Seo, 2014 is newly synonymized with Alloclubionoides cochlea (Kim et al. 2007).

The susceptibility of Dermanyssus gallinae adults, collected from poultry farms in 5 regions, to 11 acaricides was investigated. When bifenthrin and formic acid with pyridaben were diluted 100 times, bifenthrin showed 100% acaricidal activity; however, formic acid with pyridaben showed less than 20% acaricidal activity for poultry farms in 3 regions (Gyeongju, Chilgok, and Geumsan) except Yeoncheon and Anseong. Clothianidin, thiamethoxam, fenitrothion, and formic acid with pyridaben showed differences in acaricidal activity among regions. Therefore, farmers should concentrate during the selection of these acaricides. However, carbaryl, cartap hydrochloride, dichlorvos, and bifenthrin showed high activity against D. gallinae collected from poultry farms in five regions. To control D. gallinae effectively, the alternation of acaricides is necessary, and indiscriminate pesticide use should be avoided. Therefore, this study can serve as a basis for controlling D. gallinae.

The acaricidal activity of a methanolic extract and fractions from the rhizome of Cnidium officinale against Dermanyssus gallinae adults was investigated. The C. officinale methanolic extract exhibited 100% acaricidal activity after 48 h of treatment at a dose of 4,000 ppm. Gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy revealed (Z)-ligustilide as a constituent of C. officinale. Acaricidal activity was examined in three experimental tests (spray, fumigation and contact), with the spraying method being the most effective. The methanolic extract of C. officinale showed both contact and fumigant activities, though only fumigant activity was observed with (Z)-ligustilide. These results suggest that C. officinale derived material can be used for the development of a control agent for D. gallinae.