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        검색결과 63

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Light is a major external environmental factor that influences the circadian rhythm of photosynthetic organisms and various physiological phenomena, such as growth, maturation, and behavior. The number of light-reaching organisms changes depending on the season and atmospheric conditions, and the intensity and wavelength of light differ depending on the organisms inhabiting the environment. Altered light changes the circadian rhythm of fish, which is controlled by clock genes, such as period 2 (Per2), cryptochrome 1 (Cry1), and melatonin. In this study, we set the zeitgeber time (ZT; 14 light-10 dark, LD) based on the actual sunrise and sunset times and examined Per2 and Cry1 activities, levels of aralkylamine N-acetyltransferase (AANAT), and melatonin in Pholis nebulosa, a drifting seaweed species exposed to irregular light. Per2 and Cry1 levels increased during the daytime and decreased after sunset. The AANAT levels decreased during the daytime and increased during the night. Melatonin concentration was highest around midnight (ZT21, 23:30), but exhibited similar concentrations during the daytime. While the activity of Per2, Cry1, and AANAT levels exhibited a typical circadian rhythm observed in most vertebrates, melatonin concentrations did not show a significant difference between the daytime and nighttime. These findings provide insights into the circadian rhythm patterns of organisms exposed to irregular light environments, such as P. nebulosa, which differ from those of typical fish species.
        4,000원
        7.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this experiment was to investigate the effect of drip irrigation volume on tomatoes (Solanum lycopersicum L.) grown in a greenhouse using perlite medium. Plants were treated by three different irrigation treatment I0, I25, and I50 (where irrigation volume of I25 and I50 was 25% and 50% higher than I0, having limited or no leaching). Growth characteristics of plants, yield and water use efficiency were measured. The result showed that plant height, leaf length and leaf width were lowest in the I0 treated plants. However, these parameters were not statistically significant differences between the plants that were grown in the I25 and I50 treatment. Soluble solids content, acidity and dry matter of 111th, 132nd, and 143rd days harvested tomato were higher in the plants irrigated with lowest volume (I0) than the higher volume (I25 or I50). In addition, water content was lower in the 111th and 132nd days of harvested tomatoes from the I0 treatment. The number of big-size tomatoes (>180 g) was significantly higher in the I25 irrigated plants. There was no significant difference in the total number of harvested fruits among the treatments. The average fruit weight and total yield of harvested tomatoes were lowest in the I0 treated plants. The water consumption of tomato was not significantly different amongst the treatments but water use efficiency was lowest in the I0 treatment. Principal component analysis revealed that total soluble solid and acidity of tomato showed a positive correlation between each other. These results suggest that I25 was the optimum irrigation treatment for tomato based on its measured growth characteristics, yield and water use efficiency.
        4,200원
        8.
        2022.06 구독 인증기관 무료, 개인회원 유료
        This investigation aimed to assess the appetite response changes of olive flounder to starving and re-feeding conditions. Three different feeding groups (2 weeks feeding, fed; 2 weeks starving, starved; and 1 week starving and 1 week feeding, re-fed) were established to examine the changes in appetite-related genes for each group. The weight gain of the fish was highest for the fed group and lowest for the starving group. Based on the daily feed intake (DFI) and cumulative feed intake (CFI), overall food intake was found to increase in the re-fed group more than in the fed group from week 1 to week 2 of the experiment. Hypocretin neuropeptide precursor (HCRT) and galanin receptor 1 (GAL-R1) mRNA expression in the brain of olive flounder were decreased in the starved group. Corticotropin-releasing hormone (CRH) was decreased in all experimental groups, except for the fed group. However, overall leptin concentrations in the plasma did not change across groups. Considering the differences between this study and previous studies on starving and feeding, various factors (except the production and expression mechanisms of appetite-related factors in response to starving) are likely acting on the appetite responses of the fish. In this study, a 1-week re-feeding period induced substantial effects on appetite response when compared to a 2-week feeding period. These findings show that even if re-feeding is performed after starving, the unbalance caused by the re-feeding can affect various physiological changes in fish by feed intake efficiency.
        4,000원
        9.
        2021.09 구독 인증기관 무료, 개인회원 유료
        Periodontitis and periimplantitis are caused as a result of dental biofilm formation. This biofilm is composed of multiple species of pathogens. Therefore, controlling biofilm formation is critical for disease prevention. To inhibit biofilm formation, sugars can be used to interrupt lectin-involving interactions between bacteria or between bacteria and a host. In this study, we evaluated the effect of D-Arabinose on biofilm formation of putative periodontal pathogens as well as the quorum sensing activity and whole protein profiles of the pathogens. Crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy revealed that D-Arabinose inhibited biofilm formation of Porphyromonas gingivalis , Fusobacterium nucleatum , and Tannerella forsythia . D-Arabinose also significantly inhibited the activity of autoinducer 2 of F. nucleatum and the expression of representative bacterial virulence genes. Furthermore, D-Arabinose treatment altered the expression of some bacterial proteins. These results demonstrate that D-Arabinose can be used as an antibiofilm agent for the prevention of periodontal infections.
        4,000원
        11.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, importance of blockchain systems has been grown after success of bitcoin. Distributed consensus algorithm is used to achieve an agreement, which means the same information is recorded in all nodes participating in blockchain network. Various algorithms were suggested to resolve blockchain trilemma, which refers conflict between decentralization, scalability, security. An algorithm based on Byzantine Agreement among Decentralized Agents (BADA) were designed for the same manner, and it used limited committee that enables an efficient consensus among considerable number of nodes. In addition, election of committee based on Proof-of-Nonce guarantees decentralization and security. In spite of such prominence, application of BADA in actual blockchain system requires further researches about performance and essential features affecting on the performance. However, performance assessment committed in real systems takes a long time and costs a great deal of budget. Based on this motivation, we designed and implemented a simulator for measuring performance of BADA. Specifically, we defined a simulation framework including three components named simulator Command Line Interface, transaction generator, BADA nodes. Furthermore, we carried out response surface analysis for revealing latent relationship between performance measure and design parameters. By using obtained response surface models, we could find an optimal configuration of design parameters for achieving a given desirable performance level.
        4,000원
        12.
        2020.11 구독 인증기관·개인회원 무료
        Recently, a lots of studies have been conducted to imitate real meat with the factors including texture, aroma, taste, and color of meat analogues. Since the color component of meat is diverse and complex, as well as large of degree of change according to cooking, the color imitating has been still challenging. In this study, we selected up a representative meat analogue (tteok-galbi), tracked the color change at three making points as steps of batter, steaming, and cooking. In order to realize the color at these points, three plant-based natural pigments including prickly pear cactus, sweet pumpkin, and mugwort were selected, and the color with optimized ratio was applied to the tteok-galbi. As a result, it was found that 1:3:1 in the batter, 2:1:2 in steaming, and 2:1:2 in cooking were optimal ratios. The results in this study were significant in that it could apply the colors to meat analogues according to the combination of natural pigments derived from plants.
        14.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Various elements of Fabrication (FAB), mass production of existing products, new product development and process improvement evaluation might increase the complexity of production process when products are produced at the same time. As a result, complex production operation makes it difficult to predict production capacity of facilities. In this environment, production forecasting is the basic information used for production plan, preventive maintenance, yield management, and new product development. In this paper, we tried to develop a multiple linear regression analysis model in order to improve the existing production capacity forecasting method, which is to estimate production capacity by using a simple trend analysis during short time periods. Specifically, we defined overall equipment effectiveness of facility as a performance measure to represent production capacity. Then, we considered the production capacities of interrelated facilities in the FAB production process during past several weeks as independent regression variables in order to reflect the impact of facility maintenance cycles and production sequences. By applying variable selection methods and selecting only some significant variables, we developed a multiple linear regression forecasting model. Through a numerical experiment, we showed the superiority of the proposed method by obtaining the mean residual error of 3.98%, and improving the previous one by 7.9%.
        4,000원
        16.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Process mining is an analytical technique aimed at obtaining useful information about a process by extracting a process model from events log. However, most existing process models are deterministic because they do not include stochastic elements such as the occurrence probabilities or execution times of activities. Therefore, available information is limited, resulting in the limitations on analyzing and understanding the process. Furthermore, it is also important to develop an efficient methodology to discover the process model. Although genetic process mining algorithm is one of the methods that can handle data with noises, it has a limitation of large computation time when it is applied to data with large capacity. To resolve these issues, in this paper, we define a stochastic process tree and propose a tabu search-genetic process mining (TS-GPM) algorithm for a stochastic process tree. Specifically, we define a two-dimensional array as a chromosome to represent a stochastic process tree, fitness function, a procedure for generating stochastic process tree and a model trace as a string of activities generated from the process tree. Furthermore, by storing and comparing model traces with low fitness values in the tabu list, we can prevent duplicated searches for process trees with low fitness value being performed. In order to verify the performance of the proposed algorithm, we performed a numerical experiment by using two kinds of event log data used in the previous research. The results showed that the suggested TS-GPM algorithm outperformed the GPM algorithm in terms of fitness and computation time.
        4,200원
        19.
        2019.04 구독 인증기관·개인회원 무료
        우리나라에서 흰등멸구는 매년 해외로부터 비래, 정착한 후 2~3세대를 경과하며 벼의 생육 및 품질 저하에 영향을 미치는 벼의 중요 해충 중 하나이며, 비래해충의 경우 비래 후 세대에 따른 변화 양상을 정확하게 예측하는 것은 방제시기와 방제수단을 결정하는데 중요하다. 공시충은 2018년 사육실에서(25±2 ℃, 60±5% RH, L:D=16:8) 누대사육하여 사용하였다. 흰등멸구가 국내에 비래 후 3세대까지 세대증식하면서 피해를 주는 것으로 가정하여 1세대와 3세대 간의 발육과 산란 등을 조사하였으며 얻어진 결과를 토대로 생명표를 작성하였다. 약충기간은 1세대와 3세대에서 각각 14.5일, 13.6일, 암컷 성충기간은 각각 17.2일, 11.8일로 나타났으며, 우화율은 98.3%, 85.0%로 조사되었 다. 산란기간은 각각 6.8일, 6.0일이었으며 산란수는 47.5마리, 122.6마리로 세대가 늘어나면서 증가하는 것으로 나타났다. 생명표 분석 결과, 순증가율, 내적자연증가율이 각각 5배, 1.7배 증가한 것으로 나타났다.
        20.
        2018.10 구독 인증기관·개인회원 무료
        개미 사육 및 관찰을 위한 사용되는 투명 젤리형 개미사육장은 간편한 활용성으로 아동의 자연관찰 학습용 교구로 꾸준히 애용되고 있다. 하지만 투명 젤리는 다량의 수분 함유 문제뿐만 아니라 부패방지를 위해 단백질을 포함하고 있지 않기에 사육 시 단백질을 필요로 하는 산란용 여왕개미나 애벌레의 사육이 불가능하다는 단점이 있다. 이에 본 연구는 산란용 여왕개미와 애벌레의 사육이 가능한 단백질 함유 곤충 젤리를 만드는 방법을 제안하고자 한다. 단백질 공급원으로는 우유를, 부패 방지제로는 천연물 기반 키토산을 사용하였으며, 기능이 첨가된 사육용 젤리의 항균성은 곤충 대량폐사 질병인 물렁병의 원인균주(Serratia marcescens)로 테스트(in vitro)하였다. 실험군인 곤충사육용 젤리는 박토아가(1.5%,w/v)가 함유된 키토산수용액(1%,w/v)에 1:1 용량비율로 우유를 섞어 제조하며, 대조군은 키토산수용액을 제외하였다. 제조 배지는 Serratia marcescens를 도말 배양하여 효과성을 검증하였다. 그 결과 3배 희석한 균주(4.8×106CFU/ml)를 접종 후 2일간 배양한 그룹에서 대조군(키토산 없음)은 균이 많이(TNTC) 자랐으나, 실험군(키토산 있음)은 전혀 자라지 않았다. 따라서 위 실험은 키토산을 첨가하는 간단한 방법으로도 유해균의 생장 억제와 유충의 성장 촉진이 동시에 가능한 기능성 단백질 곤충젤리의 제조 가능성을 확인하였다.
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