• 식물조직배양학회지
• /
• 제24권4호
• /
• pp.239-256
• /
• 1997

Plants belonging to the category of 2n apomixis or agamospermy form embryos and seeds without the processes of normal meiosis and syngamy. Seeds produced in this way have identical genotype of their maternal parent. Three different types of agamospermy are recognized: diplospory, apospory, and adventitious (adventive) embryony. $F_1$ hybrid cultivars cannot be used as seed sources in the next ($F_2$) generation because this generation would be extremely variable as a result of genetic segregation. Hybrid vigor is also reduced in the $F_2$ generation. Therefore, parental stocks for hybrid seed production need to be maintained and cross must be continuously repeated. Agamospermic 2n apomixis would make it possible to fix the genotype of a superior variety so that clonal seeds faithfully representing that genotype could be continuously and cheaply produced independent of pollination. That is, $F_1$ hybrid seeds could be produced for many generations without loss of vigor or genotype alteration. Production of apomictic $F_1$ hybrid seed would be simplified because line isolation would not be necessary to produce seed or to maintain parental lines, and the use of male-sterile lines could be avoided. Overall, apomixis would enable a significant reduction in hybrid seed production costs. Additionally, the production of clonal seed is not only important for seed propagated crops, but also for the propagation of heterozygous fruit trees and timbers. Clonal seed would help avoid costly and time-consuming vegetative propagating methods that are currently used to ensure the large-scale production of these plants. Apomixis is scattered throughout the plant kingdom, but few important agricultural crops possess this trait Therefore, most research to date has centered on introgressing the trait of apomixis into agricultural crops such as wheat, maize, and some forage grasses from wild distant relatives by traditional cross breeding. The classical breeding approach, however is slow and often impeded by many breeding barriers. These problems could be surmounted by taking mutagenesis or molecular approach. Arabidopsis thaliana is a tiny sexually reproducing plant and is convenient in constructing and screening in molecular researches. Male-sterile mutants of Arabidopsis are particularly suitable genetic background for mutagenesis and screening for apomictic mutants. Molecular approaches towards isolating the genes controlling the apomictic process are feasible. Direct isolation of genes conferring apomixis development would greatly facilitate the transfer of this trait to wide variety of crops. Such studies are now in progress.

• KSBB Journal
• /
• 제15권6호
• /
• pp.609-614
• /
• 2000

최근 항암제로서 관심을 끌고있는 camptothecin올 생산하기 위한 희수(Camptotheca acuminata) 현탁세포 배양과 cam­p ptothecin의 생산을 촉진하는 연구를 수행하였다. 장기간 배양 으로 발생되는 이차대사산물 생산능력의 변이가 관찰되어 이 를 극복하고자 세포의 응집을 통한 camptothecin의 생산을 촉진하고자 하였다. 세포의 응집은 hybrid 배지와 sucrose 4 %일 때에 가장 많이 유도되었고, 이때 camptothecin의 생산량도 $18.04{\times}10^{-4} mg/L$로 가장 높은 생산성을 가졌다. 또한, 세포의 응집을 유도하기 위한 일환으로 교반속도를 변화시켜 이에 대한 효과를 알아보았는데, 100rpm에서 가장 많은 세포응집이 유도되었으며, camptothecin의 생산 역시 $19.4{\times}10^{-4} mg/L$로 가장 높은 결과를 나타내었다.

• 한국산업정보학회:학술대회논문집
• /
• 한국산업정보학회 2008년도 추계 공동 국제학술대회
• /
• pp.463-467
• /
• 2008

Heuristic optimization using hybrid algorithms have provided a robust and efficient approach for solving many optimization problems. In this paper, a new hybrid algorithm using adaptive genetic algorithm (aGA) and particle swarm optimization (PSO) is proposed. The proposed hybrid algorithm is applied to solve numerical optimization functions. The results are compared with those of GA and other conventional PSOs. Finally, the proposed hybrid algorithm outperforms others.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2011년도 추계학술대회
• /
• pp.162-163
• /
• 2011

This paper presents the system dynamics methodology for modeling and control the production/inventory system. Under system dynamics point of view, we can apply some production/inventory policies as if we use the control laws for dynamics systems, then the behavior of system is analyzed and evaluated to improve the performance of production/inventory system. We also utilize the hybrid modeling method for the dynamic of production system with the combination of Matlab/Simulink and Matlab/Sateflow. Finally, the numerical simulation results are carried out in Matlab/Simulink environment and compare with the results from other works. It is shown that our approach can obtain some good performances (such as operational cost, stability of inventory, customer service level).

• International journal of advanced smart convergence
• /
• 제12권4호
• /
• pp.361-369
• /
• 2023

Achieving realistic visual quality while maintaining optimal real-time rendering performance is a major challenge in evolving computer graphics and interactive 3D applications. Normal mapping, as a core technology in 3D, has matured through continuous optimization and iteration. Hybrid normal mapping as a new mapping model has also made significant progress and has been applied in the 3D asset production pipeline. This study comprehensively explores the hybrid normal techniques, analyzing Linear Blending, Overlay Blending, Whiteout Blending, UDN Blending, and Reoriented Normal Mapping, and focuses on how the various hybrid normal techniques can be used to achieve rendering performance and visual fidelity. performance and visual fidelity. Under the consideration of computational efficiency, visual coherence, and adaptability in different 3D production scenes, we design comparative experiments to explore the optimal solutions of the hybrid normal techniques by analyzing and researching the code, the performance of different hybrid normal mapping in the engine, and analyzing and comparing the data. The purpose of the research and summary of the hybrid normal technology is to find out the most suitable choice for the mainstream workflow based on the objective reality. Provide an understanding of the hybrid normal mapping technique, so that practitioners can choose how to apply different hybrid normal techniques to the corresponding projects. The purpose of our research and summary of mixed normal technology is to find the most suitable choice for mainstream workflows based on objective reality. We summarized the hybrid normal mapping technology and experimentally obtained the advantages and disadvantages of different technologies, so that practitioners can choose to apply different hybrid normal mapping technologies to corresponding projects in a reasonable manner.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.251.2-251.2
• /
• 2013

Natural photosynthesis utilizes two proteins, photosystem I and photosystem II, to efficiently oxidize water and reduce NADP+ to NADPH. Artificial photosynthesis which mimics this process achieve water splitting through a two-step Z-schematic water splitting process using man-made synthetic materials for hydrogen fuel production. In this study, Z-scheme system was achieved from the hybrid materials which composed of hydrogen production part as photosystem I protein and water oxidizing part as semiconductor BiVO4. Utilizing photosystem I as the hydrogen evolving part overcomes the problems of existing hydrogen evolving p-type semiconductors such as water instability, expensive cost, few available choices and poor red light (>600 nm) absorbance. Some problems of photosystem II, oxygen evolving part of natural photosynthesis, such as demanding isolation process and D1 photo-damage can also be solved by utilizing BiVO4 as the oxygen evolving part. Preceding research has not suggested any protein-inorganic-hybrid Z-scheme composed of both materials from natural photosynthesis and artificial photosynthesis. In this study, to realize this Z-schematic electron transfer, diffusion step of electron carrier, which usually degrades natural photosynthesis efficiency, was eliminated. Instead, BiVO4 and Pt-photosystem I were all linked together by the mediator gold. Synthesized all-solid-state hybrid materials show enhanced hydrogen evolution ability directly from water when illuminated with visible light.

• 반도체디스플레이기술학회지
• /
• 제20권3호
• /
• pp.57-64
• /
• 2021

The domestic semiconductor industry can produce various products that will satisfy customer needs by diversifying assembly parts and increasing compatibility between them. It is necessary to improve the production line as a method to reduce the work-in-process inventory (WIP) in the assembly line, the idle time of the worker, and the idle time of the process. The improvement of the production line is to balance the capabilities of each process as a whole, and to determine the timing of product input or the order of the work process so that the time required between each process is balanced. The purpose of this study is to find the optimal WIP and buffer size through SA (Simulated Annealing) that minimizes lead time while matching the number of two parts in a parallel assembly line with bottleneck process. The WIP level and buffer size obtained by the SA algorithm were applied to the CONWIP and DBR systems, which are the existing production systems, and the simulation was performed by applying them to the new hybrid production system. Here, the Hybrid method is a combination of CONWIP and DBR methods, and it is a production system created by setting new rules. As a result of the Simulation, the result values were derived based on three criteria: lead time, production volume, and work-in-process inventory. Finally, the effect of the hybrid production method was verified through comparative analysis of the result values.

• Bulletin of the Korean Chemical Society
• /
• 제20권9호
• /
• pp.993-998
• /
• 1999

The concurrent production of methanol and dimethyl ether from carbon dioxide hydrogenation has been studied under various reaction conditions. First, the methanol synthesis was compared with the concurrent production method. For the methanol synthesis, the ternary mixed oxide catalyst (CuO/ZnO/Al2O3) was used and for the coproduction of methanol and dimethyl ether, silica-alumina was mixed with the methanol synthesis catalyst to be a hybrid catalyst. The results show that the co-production provides much higher per-pass yield than methanol synthesis even at very short contact time. The effects of temperature, contact time, pressure and catalyst hybrid ratio on the product yields and selectivities were also determined in the co-production.

• 한국미생물·생명공학회지
• /
• 제17권3호
• /
• pp.257-262
• /
• 1989

착색용 포도품종(Vitis hybrid)의 조직으로부터 callus를 유도하고 액체 진탕배양을 행하여 세포 생육 및 anthocyanin의 생성에 미치는 각종 인자들에 대하여 조사한 결과 광조사량 및 무기질소원 농도가 가장 큰 영향을 미치는 것으로 나타났다. 즉, 광조사량이 10,000lux 였을 때는 암소에서 배양했을 때보다 anthocyanin 생성량은 약 2배 증가하였다. 또한 기존 MS 배지의 무기질소원 농도를 20배로 감소시켜 배양했을 때 전체 anthocyanin 생성량은 약 5-6배, 건조 중량당 함량은 약 16배 증가함을 알 수 있었다. 또한 무기질소원으로 nitrate만을 첨가했을 때 가장 높은 수율을 나타냈다. 고농도의 Co$^{2+}$, Fe$^{2+}$와 Miller 배지, Gamborg 배지 등이 anthocyanin 생산에 적합한 것으로 나타났으며, MS medium 및 modified MS medium을 이용한 2단계 배양을 시도하여 약 40mg/flask의 높은 anthocyanin 수율을 얻을 수 있었다.

• 품질경영학회지
• /
• 제47권4호
• /
• pp.823-835
• /
• 2019

Purpose: This study deals with a production planning and scheduling problem to minimize the total weighted tardiness on hybrid flow shop with sets of non-identical parallel machines on stages, where parallel machines in the set are dedicated to perform specific subsets of jobs and sequence-dependent setup times are also considered. Methods: A two-stage approach, that applies MILP model in the 1st stage and dispatching rules in the 2nd stage, is proposed in this paper. The MILP model is used to assign jobs to a specific machine in order to equalize the workload of the machines at each stage, while new dispatching rules are proposed and applied to sequence jobs in the queue at each stage. Results: The proposed two-stage approach was implemented by using a commercial MILP solver and a commercial simulation software and a case study was developed based on the spark plug manufacturing process, which is an automotive component, and verified using the company's actual production history. The computational experiment shows that it can reduce the tardiness when used in conjunction with the dispatching rule. Conclusion: This proposed two-stage approach can be used for HFS systems with dedicated machines, which can be evaluated in terms of tardiness and makespan. The method is expected to be used for the aggregated production planning or shop floor-level production scheduling.