• Title/Summary/Keyword: Stream Characteristic

Search Result 331, Processing Time 0.03 seconds

Water Level Control of PWR Steam Generator using Knowledge Information and Neural Networks (지식정보와 신경회로망을 이용한 가압경수로 증기발생기 수위제어)

  • Bae, Hyeon-Bae;Woo, Young-Kwang;Kim, Sung-Shin;Jung, Kee-Soo
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.13 no.3
    • /
    • pp.322-327
    • /
    • 2003
  • The water level of a steam generator of pressurized light water nuclear Power generator is known as a subject whose control is difficult because of a shrinking and swelling effect that is been mutually contradictory in a variation of feed water. In this paper, a neural network model selects first coordinative controller by a inappropriate gain of two PI controllers and the selected controller's gain is tuned by a fuzzy self-tuner. Model inputs consist of the water level, the feed water, and the stream flow. One controller of both coupling controllers whose gain is handled firstly is decided based upon above data. The proposed method can analyze patterns of signals using the characteristic of neural networks and select one controller that needs to be tuned through the observed result in this paper. If one controller between both the water level controller and the feed water controller is selected by the neural network model then a gain of the PI controller is suitably tuned by the fuzzy self-tuner. Rules of the fuzzy self-tuner drew from the pattern of input and output data. In the summary, the goal of this Paper is to select the suitable controller and tune the control gain of the selected controller suitably through such two processes.

Dispersion of Toxic Elements in the Area Covered with Uranium-Bearing Black Shales in Korea (함(含)우라늄 흑색(黑色)세일 분포지역(分布地域)에서의 유독성원소(有毒性元素)들의 분산(分散)에 관한 지구화학적(地球化學的) 연구(硏究))

  • Chon, Hyo-Taek;Jung, Myung-Chae
    • Economic and Environmental Geology
    • /
    • v.24 no.3
    • /
    • pp.245-260
    • /
    • 1991
  • Surficial dispersion patterns of heavy metals and toxic elements (U, Mo, Cu, Zn, Fe, Mn, Co, Cr, V, Ni, Pb, and Cd) were investigated in the Dukpyungri, Goesan area covered with low grade uranium-bearing black shales. Maximum abundance of U in the black shale was 455ppm. Radioactivity was counted at a maximum of 7cps in black shales, and was less than 0.5cps in shales, slates, and oil shales of the control areas. Enrichment of Mo, V, Cu, Zn, Cd, and Pb in black shales is particularly characteristic compared with shales, slates, and oil shales of the control areas, whereas contents of Mn, Cr, Co, and Th in all rock samples tend to be almost similar. Residual top soils (0~15cm depth) over black shales show high contents of Mo, Cu, Zn, Ni, Cd, and V in comparison with the control areas. Contents of trace elements in subsoils (15~30cm depth) were higher about one and half times than those in topsoils. Average contents of Mo, Cu, Pb, Zn, Cd and V in garden soil and playground soil of an elementary school in Dukpyungri, Goesan area, were high about two to fifteen times compared with the control areas. Contents of trace elements in stream sediments were higher from two to eight times than those in residual soils. Sodium, AI, K, V, Cr, and Fe were more enriched in the roots of pine than in the twigs of pine. Contents of Li, AI, V, Ni, Cd, Fe, and Co were higher in the roots of azalea than in the twigs of azalea. Enrichment of P, Ca, and Mg was remarkable in the twigs of both pine and azalea. Biological absorption coefficients for essential elements (Zn, P, Mn, Ca and K)tend to be high, whereas those for the non-essential elements.(Ba, Ti, V, and Mo) and toxic elements(Cr, Co, Pb and Ni) be low. Less mobile elements (Pd, Cd, and Co) tend to show anomalies with higher contrast than more mobile elements(Mo, V, Zn, Cu and Ni) in the area covered with black shales.

  • PDF

Tension Test on the Bar-type Anti-buoyancy Anchors in the Weathered Rock (풍화암에 시공된 Bar Type 부력저항 앵커의 인장 시험)

  • Park, Chan-Duk;Lee, Kyu-Hwan;Ryu, Nam-Jae;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.8 no.1
    • /
    • pp.175-181
    • /
    • 2004
  • This study is about a section where underground water level occurs at the underground 5m depth by the excavation of the ground, as a stream is adjacent to a excavation section of High Speed Railway ${\bigcirc}{\bigcirc}$ Station construction sections and a reservoir being always full of water is located at the left side of the construction section. Therefore this test is executed for the design and construction of buoyance anchors able to permanently prevent buoyance by the underground water level at working and for the stable construction and permanent smooth maintenance of structures. In this test, bar type anchors are divided according to their length and standard to execute test-anchor test, and In spot test, 9 test-anchors test, proof test to construction process, suitability test and acceptance test are executed 4 times to 9 test-anchors by dividing anchors according to the length of permanent anchor, the outer diameter of bar and boring diameter. Standard motion characteristic centering on load transmission and break mechanism of bar-type anchors for the prevention of buoyance will be showed in the thesis.

A Study on the Development of SSB Modem (디지털 SSB 모뎀 개발에 관한 연구)

  • Kim, Jeong-Nyun
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.11 no.10
    • /
    • pp.1852-1857
    • /
    • 2007
  • The SSB modem performs the modulation process which converts the digital voltage level to the audible frequency band signal and the demodulation process which converts reversely the audible frequency signal to the digital voltage level. The modulator and the demodulator are implemented with a single DSP chip. Because of the SSB specific character, the distortion occurs when the frequency is changed. This distortion has no effect on voice communication but it has an significant effect on data communication. In other words, it is impossible to send data stream with adjacent 2 periods. Therefore, in case of using 2-tone FSK, it is needed to send at least 3 periods to transmit 1 bit. Therefore we implemented the modem using modified phase-delay shift keying to transmit 1 tone signal for high speed transmission. In the 1200[bps] mode, it generates 0, $187{\mu}s$, delay time at 1.3kHz symbol frequency, and in the 2400[bps] mode, 0, $70{\mu}s\;130{\mu}s\;200{\mu}s$, delay time at 1.5kHz symbol frequency. Finally, in the maximum 3600[bps] mode, it generates 0, $100{\mu}s\;160{\mu}s\;250{\mu}s$ 2.0kHz symbol frequency. The measured results of the implemented SSB modem shows a good transfer functional characteristic by spectrum analyzer, almost same bandwidth in pass band and 20dB higher SNR comparing the emu FACTOR and American CLOVER and in the experimental transmitting test, we verified the transmitted data is received correctly in platform.

The establishing process of Keyongyegimunrok(經義記聞錄) by Namdang Han Wonjin and the characteristic of illustrated accounts of Heart-mind theory (남당(南塘) 한원진(韓元震)의 『경의기문록(經義記聞錄)』 성립 과정과 심성론 도설(圖說)의 특징)

  • Lee, Chang-il
    • The Journal of Korean Philosophical History
    • /
    • no.35
    • /
    • pp.131-164
    • /
    • 2012
  • This paper is to make a generalization of Keyongyegimunrok(經義記聞錄) by Namdang Han Wonjin(1682~1751) whose historical positions of philosophy were contained, and to examine its established periods and the summaries of Ligi-Simseong Doseol(理氣心性圖說, illustrated Account of principle, Vital force, and Heart-mind) given in Appendix of Chap. 6. Total seventeen explanatory diagrams cover over the theory of principle and material force, theory of Heart-mind, theory of cultivation. These explanatory diagrams were produced systematically and easily to understand the pursuits of study, so-called Ho-hak(湖學), since Namdang becoming a member of the Yellow River(黃江) school. The philosophical argumentations of Namdang was usually succeeded by the orthodox stream of Ki-ho(畿湖) School transmitted from Ii, Song Si-yeol, Gwon Sang-ha. Ligi-wollyu-do(理氣源流圖), Ligi-dongjeong-do(理氣動靜圖), irwon-bunsu-do(一原分殊圖, 4 diagrams) are diagrams equivalent to Ki-ho School's ontology. As Ki-ho School's theory of Heart-mind, there are Seongjeong-hoenggan-do(性情橫看圖), Seongjeong-sugan-do(性情竪看圖), Seongjeong-chonghwoi-do(性情總會圖), Oseonghoju-do (五性互主圖), Oseongchubon-do(五性推本圖), Simseongmyohap-do (心性妙合圖), Simseongiji-do(心性二岐圖), Jungyongcheonmyeong-do(中庸天命圖), Insim dosim-do(人心道心圖), focusing on Simtongseongjeong-do(心統性情圖), and last diagram is Wihakjibang-do(爲學之方圖), which adapted from the diagram established by Ii and Song Si-yeol. The significance of Keyongyegimunrok(經義記聞錄) is comprehensive of the pursuits of the Yellow River school's studies, and provides evidence of a leading figure in Ho-hak.

Ecological Characteristic of Clithon retropictus inhabitating in Yeoncho River in Southern Coastal Area (남해안 연초천에 서식하는 기수갈고둥의 생태적 특성 연구)

  • Lee, Soo-Dong;Kim, Mi-Jeong;Kim, Ji-Suk
    • Korean Journal of Environment and Ecology
    • /
    • v.32 no.6
    • /
    • pp.591-602
    • /
    • 2018
  • Clithon retropictus has been designated as an endangered wildlife Class II due to its high value as a biological indicator species capable of judging environmental quality such as salinity, water flow, and ground conditions. However, basic research on its physiological and ecological characteristics is still lacking. As such, this study intended to examine the impact of environmental conditions such as salinity and soil particle size on the size and density of Clithon retropictus at the Yeoncho river estuary. The investigation of the salinity, which is a key variable that affects the distribution of organisms in the estuary, showed that Clithon retropictus could grow at a salinity ranging from 0#x2030; (freshwater) to 25‰ (brackish water). The coarse gravel (19-75mm) tended to increase nearer the upper stream (under the Yeoncho weir), while the proportion of particles smaller than sand (less than 19mm) increased toward the downstream. The population and the size of the individuals decreased rapidly in the downstream where water stagnated near the Yeoncho weir, and the salt water joined. The results indicated that Clithon retropictus had a high tolerance to salinity, but the adaptability was weaker toward the extremes since the population, and the size tended to decrease as the salinity increased. The correlation analysis revealed that both salinity and soil particle size affected the population and individual size. The correlation between the individual size and salinity was -0.242 (P <0.01), indicating that the size decreased with increasing salinity. The correlation between individual size and coarse gravel having a particle size of 19mm or more was 0.420 (P <0.01), indicating that the size increased with increasing the particle size.

Analysis of Musical Characteristics and Changes in Different Periods on Yoon-Sang's Music (윤상의 곡에 나타난 음악적 특징과 시대별 변화)

  • Park, Ji-Eun;Chung, Jae-Youn
    • Journal of Korea Entertainment Industry Association
    • /
    • v.15 no.1
    • /
    • pp.63-73
    • /
    • 2021
  • This study aims to analyze music of Yoon-sang, as a part of musical research, which is the most fundamental approach among academic studies on Korean popular music. Yoon-Sang is a representative composer, who has gone through the 1980s to the present. The result of analysis of 21 songs created by Yoon-Sang showed that his songs are mostly characterized by tonal music, in which chord relationships develop focusing on keynotes. The reason why his music does not sound uniform pursuing stability is he properly added the progression of chromatic chords, based on diatonic chords and melodies. Dominant 7th chord and diminished 7th chord are used the most among diverse techniques adding chromatic colors. Along with these chords, chromatic intervals are used not only in chord progression but also in melodies. The successive, ascending or descending movement of the base line is his common composition and arrangement technique revealed in every song. One of formal changes with the stream of the times is that the number of measured in the pre-chorus and interlude that were of great importance in his songs of the 1990s decreased over time. With regard to harmonic changes, whereas modulation between parts was applied to his 2 songs created in the 2010s. Yoon-Sang's music had one strong tonality overall, but his music began to have more than two tonalities starting the 2010s, and this is a big variation in his music.

A Generation and Matching Method of Normal-Transient Dictionary for Realtime Topic Detection (실시간 이슈 탐지를 위한 일반-급상승 단어사전 생성 및 매칭 기법)

  • Choi, Bongjun;Lee, Hanjoo;Yong, Wooseok;Lee, Wonsuk
    • The Journal of Korean Institute of Next Generation Computing
    • /
    • v.13 no.5
    • /
    • pp.7-18
    • /
    • 2017
  • Recently, the number of SNS user has rapidly increased due to smart device industry development and also the amount of generated data is exponentially increasing. In the twitter, Text data generated by user is a key issue to research because it involves events, accidents, reputations of products, and brand images. Twitter has become a channel for users to receive and exchange information. An important characteristic of Twitter is its realtime. Earthquakes, floods and suicides event among the various events should be analyzed rapidly for immediately applying to events. It is necessary to collect tweets related to the event in order to analyze the events. But it is difficult to find all tweets related to the event using normal keywords. In order to solve such a mentioned above, this paper proposes A Generation and Matching Method of Normal-Transient Dictionary for realtime topic detection. Normal dictionaries consist of general keywords(event: suicide-death-loop, death, die, hang oneself, etc) related to events. Whereas transient dictionaries consist of transient keywords(event: suicide-names and information of celebrities, information of social issues) related to events. Experimental results show that matching method using two dictionary finds more tweets related to the event than a simple keyword search.

Biodiversity Changes and Community Characteristics of Benthic Macroinvertebrates in Weir Section of the Nakdong River, South Korea (낙동강 보 구간 저서성 대형무척추동물의 생물다양성 변화와 군집 특성)

  • Jung, Sang Woo;Kim, Yoon-Ho;Lee, Jae-Ha;Kim, Dong-Gun;Kim, Min-Kyung;Kim, Hyun-Mac
    • Korean Journal of Environment and Ecology
    • /
    • v.36 no.2
    • /
    • pp.150-164
    • /
    • 2022
  • The objective of this study is to analyze the biodiversity changes and characteristics of the benthic macroinvertebrate community in the Nakdong River with eight weirs, which was constructed as one of the Four Major River Restoration Projects from May to October 2020. The study also includes the analysis of changes in the major groups of benthic macroinvertebrates for about ten years, from 2010 to 2020. The surveys collected 97 species of benthic macroinvertebrates belonging to 83 genera, 52 families, 18 orders, five classes, three phyla, and 128.1 individuals/m2. Chironomidae sp. and Tubificidae spp., which are pollutant indicators, dominated throughout the sections. The community analysis result shows the average dominant index and the diversity index of 0.62±0.20 and 1.87±0.63, respectively, and indicated the most stability of the freshwater ecosystem in the upper stream of the Nakdong River. The survey showed dominance by Chironomidae sp. at the center of the Nakdong River weir and the most unstable community in Chilgok and Gangjeong Goryeong weirs. The results of the community stability analysis showed a high distribution of the characteristic group I with high resilience and resistance and small distribution of characteristic group III with low resistance and resilience, indicating a very unstable condition of communities in the Nakdong River weir section. Predators were relatively abundant among the functional feeding groups (FFGs), whereas shredders, gathering-collectors, and filtering-collectors were relatively lower. Among the habitat orientation groups (HOGs), burrowers and climbers were dominant, indicating a wide distribution of groups in ecosystems with low dissolved oxygen. An endangered species level II of Macromia daimoji was found in Sangju and Nakdan weirs. The analysis results for 10 years from 2010 showed that the number of species and populations increased immediately after the dam construction but plummeted in 2016 and are now stabilizing. Chironomidae spp. has been dominant in all sections over the past 10 years, and they are currently maintained at a rate of about 50%. The EPT groups have decreased significantly since 2011, and the Plecoptera and Trichoptera of the group have not yet been restored. The population of Tubificidae spp. showed an increase after construction was completed in 2012 and drastically increased in 2015 and 2020. The species of Cristaria plicata, designated as endangered species level I, has not been observed since 2011 in Hapcheon Changnyeong weir. Moreover, Macromia daimoji was rarely observed in seven weirs until 2015, and it has been confirmed that the current distribution habitat has decreased rapidly.

Nutrient Recovery from Sludge Fermentation Effluent in Upflow Phosphate Crystallization Process (상향류 인 결정화공정을 이용한 슬러지 발효 유출수로 부터의 영양소 회수)

  • Ahn, Young-Ho
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.28 no.8
    • /
    • pp.866-871
    • /
    • 2006
  • The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.