• Title/Summary/Keyword: unstable plant

Search Result 176, Processing Time 0.023 seconds

Challenges in Green Innovation Policy after the Fukushima Nuclear Accident

  • Wada, Tomoaki
    • STI Policy Review
    • /
    • v.4 no.1
    • /
    • pp.135-161
    • /
    • 2013
  • This paper examines Japan's Science and Technology (S&T) Basic Plans in accordance with its S&T Basic Law. The Basic Plans promote two major innovation (Green Innovation and Life Innovation) towards the creation of new markets and jobs, specifically under the Fourth S&T Basic Plan enacted on August 2011. Successful smart community demonstration projects at four urban localities were launched under plans to promote Green Innovation research and development of renewable energy technologies. However, the expectation that renewable energy such as solar or wind power can replace nuclear power is not backed by sufficient evidence. Furthermore, the electricity produced by these sources is expensive and unstable owing to its reliance on weather conditions. The Fukushima nuclear power plant accident on March 2011 has also seriously affected Japan's future energy plans. According to a government estimate, electricity charges would double if nuclear power generation were abandoned, imposing a heavy burden on the Japanese economy. Japan is in need of energy policies designed on the basis of more far-sighted initiatives.

Implementations of the variable structure control system using neural networks (신경회로망을 이용한 가변 구조 제어 시스템의 구현)

  • Yang, Oh;Yang, Hai-Won
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.33B no.8
    • /
    • pp.124-133
    • /
    • 1996
  • This paper presents the implementation of variable structure control system for a linear or nonlinear system using neural networks. The overall control system consists of neural network controller and a reaching mode controller. While the former approximates the equivalent control input on the sliding surface, the latter is used to bring the entire system trajectories toward the sliding surface. No supervised learning procedures are needed and the weights of the neural network are tuned on-line automatically. The neural netowrk-based variable structure control system is applied to a nonlinare unstable inverted pendulum system through computer simulations, and implemented using a microcomputer (80486-50MHz) and applied to the DC servomotor position control system. Simulation and experimental results show the expected approximation sliding property is occurred. The proposed controller is compared with a PID controller and shows better performance than the PID controller in abrupt plant parameter change.

  • PDF

Adaptive Fuzzy Control of Helicopter (헬리콥터의 적응 퍼지제어)

  • 김종화;장용줄;이원창;강근택
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 2001.05a
    • /
    • pp.144-147
    • /
    • 2001
  • This paper presents adaptive fuzzy controller which is uncertainty or unknown variation in different parameters with nonlinear system of helicopter. The proposed adaptive fuzzy controller applied TSK(Takagi-Sugeno-Kang) fuzzy system which is not only low number of fuzzy rule, and a linear input-output equation with a constant term, but also can represent a large class of nonlinear system with good accuracy. The adaptive law was designed by using Lyapunov stability theory. The adaptive fuzzy controller is a model reference adaptive controller which can adjust the parameter $\theta$ so that the plant output tracks the reference model output. First of all, system of helicopter was considered as stopping state, and design of controller was simulated from dynamics equation with stopping state. Results show that it is controlled more successfully with a model reference adaptive controller than with a non-adaptive fuzzy controller when there is a modelling error between system and model or a continuous added noise in such unstable system.

  • PDF

Plant Community Structure of Evergreen Broad-Leaved Forest in (Mt.)Pulgapsan, Korea (불갑산 상록활엽수림의 식물군집구조)

  • 오구균;지용기
    • Korean Journal of Environment and Ecology
    • /
    • v.9 no.1
    • /
    • pp.30-41
    • /
    • 1995
  • Vegetational structure were investigated for evergreen broad-leaved forest in (Mt.) Pulgapsan. Forty plots were classified into five groups, which were Aphananthe aspera community, Neolitesea sericea -Aphananthe aspera - Torreya nucifera community, deciduous broad-leaved forest group. Quercus aliena community, Quercus aliena - Quercus variabilis community by the TWINSPAN and DCA ordination techniques. But the vegetation of (Mt.)Pulgapsan was seem to be unstable structure of seral stage. Neolitsea sericea showed positive correlation to Aphananthe aspera and negative correlation to Quercus aliena. Quercus variabilis, Garpinus tschonoskii.

  • PDF

Study on the Characteristics of Low Level Atmosphere Observed in Pusan Coastal Ares (부산연안에서 관측된 저층대기의 특성에 관한 연구)

  • 전병일;김유근
    • Journal of Environmental Science International
    • /
    • v.7 no.2
    • /
    • pp.195-202
    • /
    • 1998
  • The low level atmospheric obsewation carried out to Investigate magnitude, formation and dissipation of nocturnal surface Inversion layer, also to survey relation to each meterological parameter In Inversion layer at Pusan power plant for Oct. 13, 1996. As coastal area, the surface Inversion layer height was relatively high(186m), and after sunset unstable layer formated firom surface to around 40m, and the Inversion layer was left still in the upper layer. The surface Inversion layer dissipated at 0920LST perfectly. The layer that strong Inversion layer was formated, showed steep variation of potential temperature and wand speed and relative humidity.

  • PDF

Multilayer Stereo Image Matching Based upon Phase-Magnitude an Mean Field Approximation

  • Hong Jeong;Kim, Jung-Gu;Chae, Myoung-Sik
    • Journal of Electrical Engineering and information Science
    • /
    • v.2 no.5
    • /
    • pp.79-88
    • /
    • 1997
  • This paper introduces a new energy function, as maximum a posteriori(MAP) estimate of binocular disparity, that can deal with both random dot stereo-gram(RDS) and natural scenes. The energy function uses phase-magnitude as features to detect only the shift for a pair of corrupted conjugate images. Also we adopted Fleet singularity that effectively detects unstable areas of image plant and thus eliminates in advance error-prone stereo mathcing. The multi-scale concept is applied to the multi laser architecture that can search the solutions systematically from coarse to fine details and thereby avoids drastically the local minima. Using mean field approximation, we obtained a compact representation that is suitable for fast computation. In this manner, the energy function satisfies major natural constraints and requirements for implementing parallel relaxation. As an experiment, the proposed algorithm is applied to RDS and natural stereo images. As a result we will see that it reveals good performance in terms of recognition errors, parallel implementation, and noise characteristics.

  • PDF

NMR Study of Consensus DNA-binding Site for Arabidopsis thaliana Class I Transcription Factor AtTCP1

  • Choi, Yong-Geun;Kim, Hee-Eun;Lee, Joon-Hwa
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.17 no.2
    • /
    • pp.76-80
    • /
    • 2013
  • The TCP domain is a DNA-binding domain present in plant transcription factors and has a similar structural feature to the bHTH motif of eukaryotic transcription factors. The imino proton exchange study has been performed for the DNA duplex containing the consensus DNA-binding site for the AtTCP11 transcription factor. The first two base pairs in the consensus 5'-GTGGG-3' sequence are relatively very unstable but lead to greater stabilization of the neighboring two G C base pairs. These unique dynamic features of the five base pairs in the consensus DNA sequence might play crucial roles in the effective DNA binding of the AtTCP11 protein.

Characteristics of Flow Induced Noise from a Ball Valve Used for a Gas Pipeline Using an Acoustic Camera (음향 카메라를 이용한 가스 파이프라인 볼밸브 유동소음 특성)

  • KIM, CHUL-KYU;LEE, SANG-MOON;JANG, CHOON-MAN
    • Journal of Hydrogen and New Energy
    • /
    • v.28 no.1
    • /
    • pp.106-112
    • /
    • 2017
  • The present study describes flow induced noise generated from a ball valve used for a gas pipeline. Noise generation from a ball valve mainly induces by interference between unstable(or fluctuating) leakage flow and pipe wall when the ball valve is working closed or opened. To measure the positions of the noise source and the amplitude of noise with respect to measuring frequencies, a commercial acoustic camera is introduced. Noise characteristics generated by the ball valve have been performed by four valve opening rates: 30, 50, 70 and 100 percents. It is noted that 100 percent opening rate means that the valve is fully opened. Throughout the experimental measurements using the acoustic camera, the location of the noise source and the noise amplitude with respect to the frequencies for the test ball valve are clearly evaluated. It is found that the dominant frequencies come from the fluctuating flow at the downstream of the ball valve for four opening rates are observed between 3,000Hz and 3,200Hz. Maximum noise amplitude comes from the ball valve reaches 75dB at the valve opening rate of 50 percent.

Seedling Stand Influenced by Water Management after Seeding and Seed Soaking with Plant Growth Regulators in Direct Wet Seeding Rice

  • Back, Nam-Hyun;Kim, Sang-Su;Kang, Si-Yong;Choi, Min-Gyu;Shin, Hyun-Tak;Kwon, Tae-Oh
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.44 no.3
    • /
    • pp.225-229
    • /
    • 1999
  • Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

  • PDF

Distribution Pattern of Deschampsia antarctica, a Flowering Plant Newly Colonized around King Sejong Station in Antarctica (남극 세종기지 주변에 새로이 정착한 현화식물 남극좀새풀 (Deschampsia antarctica)의 개체군 공간분포)

  • Kim, Ji-Hee;Chung, Ho-Sung
    • Ocean and Polar Research
    • /
    • v.26 no.1
    • /
    • pp.23-32
    • /
    • 2004
  • As a baseline survey for long-term monitoring on environmental change around the Antarctic King Sejong Station, distribution pattern of Deschampsia antarctica Desv., a flowering plant newly colonized were investigated qualitatively and quantitatively in both austral summer 2002 and 2003. Dispersal of the seeds and vegetative leaves by skuas might lead to the colonization into this area from neighbors in Maxwell Bay. The pioneer populations were observed around ponds and a stream of the Sejong Point in January 2002, and the maximum dispersal area was four times expanded after a year. Most of the populations were formed on the stable and well-drained substrate, which consisted of moss carpet of Sanionia georgico-uncinata (65%) and pebbles (25%), while only a few young individuals were observed on the unstable and watertight silt-sandy area. Especially, S. georgico-uncinata was being effectively utilized as their primary substrate with the soft, coarse and water-contained leaves. Also the perennial mature plants of D. antarctica were mainly formed on the moss carpet rather than pebbles. A few individuals were grown on other mosses of Polytrichastrum alpinum, Bryum pseudotriquetrum, Pohlia cruda, and Conostomum magellanicum and on a liverwort of Cephaloziella varians. We expect that dispersal of D. antarctica and the following succession to grass field will be countinuously and dynamically proceeded in this area, with the characteristics of ecological niche against the initial moss populations, on the similar continuity of environmental conditions. The continuous observations are needed with establishment of database on environmental change of micro-habitats, e.g. the water content and nutrients of soil and the underground temperature and permafrost.