• Title/Summary/Keyword: Black-out time

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Energy-Aware Data Compression and Transmission Range Control Scheme for Energy-Harvesting Wireless Sensor Networks (에너지 수집형 무선 센서 네트워크를 위한 에너지 적응형 데이터 압축 및 전송 범위 결정 기법)

  • Yi, Jun Min;Oh, Eomji;Noh, Dong Kun;Yoon, Ikjune
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.4
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    • pp.243-249
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    • 2016
  • Energy-harvesting nodes in wireless sensor networks(WSNs) can be exhausted due to a heavy workload even though they can harvest energy from their environment. On contrast, they can sometimes fully charged, thus waste the harvested energy due to the limited battery-capacity. In order to utilize the harvested energy efficiently, we introduce a selective data compression and transmission range control scheme for energy-harvesting nodes. In this scheme, if the residual energy of a node is expected to run over the battery capacity, the node spends the surplus energy to exploit the data compression or the transmission range expansion; these operations can reduce the burden of intermediate nodes at the expanse of its own energy. Otherwise, the node performs only basic operations such as sensing or transmitting so as to avoid its blackout time. Simulation result verifies that the proposed scheme gathers more data with fewer number of blackout nodes than other schemes by consuming energy efficiently.

Development of Natural Color of Bleached Hanji Dyed with Rice Straw Extractives (볏짚 추출물을 이용한 한지의 천연색 발현)

  • 최태호;이연숙
    • Journal of Korea Foresty Energy
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    • v.22 no.3
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    • pp.43-48
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    • 2003
  • Black liquor staining for the development of natural color of bleached Hanji caused problems of discoloration and degradation. This study was carried out not only to complement these problems but also to develop natural dyeing method that was similar to the color of unbleached Hanji, through the dyeing of rice straw extractives. The dyeing properties of Hanji were influenced more by dyestuffs extraction method than extraction and dyeing time. Dyeing ability of hot water extractives was superior to cold-water extractives. Without the relation to the time of extraction and dyeing, the color of Hanji dyeing hot water extractives were similar to the control, and the color of Hanji dyed for 45 min with hot water extractives that extracted for 120 min, were almost same as the control. As natural dyestuffs, hot water extractives of rice straw showed that excellent dyeing ability for the development of various natural colors similar to unbleached Hanjis.

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Cultivating Status of Paeonia lactiflora Pallas in Central Part of Gyeong Bug Province (경북 중부지역에서의 작약 재배실태)

  • Kim, Se-Jong;Park, So-Deuk;Whang, Wheong-Baeg;Kim, Jae-Cheol
    • Korean Journal of Medicinal Crop Science
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    • v.3 no.3
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    • pp.259-264
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    • 1995
  • This study was carried out to find cultivation condition of peony in Euiseong district from 1994 to 1995. 1. Age distribution in cultivation of peony was from 30's to 50's and cultivated years was mainly from 5 years to 10 years, but there was more than 15 years 2. Cultivating area per house hold were 1300 pyeong average, there were moderate $400{\sim]1000$ pyeong and also those are occupied 22.6% more than 2000 pyeong. 3. The mothods of transplanting in Euiseong peony which Euiseong district was mostly divided peony but Yeongchen district used seedling stock. No. of sprout was mostly $3{\sim}4$ and planting time was mainly from Mid to Late of October. 4. The percentage of sterilization of soil and seedling stock was 77. 4%, in mulching by vinyl in tran­splanting 64. 5% in black vinyl and 25. 8% in white one. 5. Number of plant in peony planting was $3000{\sim}4000$ plant per l0a even more there was more than 8000 plant. 6. Chemical spraying time in peony field was 2 time in $1{\sim}2$ years cultivating, and $3{\sim}4$ time in $3{\sim}4$ years one. 7. Condition of fertilizer application in peony field was 40% in non-application, but $56.7{\sim}76.7%$ in 2 year to 3 years, and the time of fertilizer was mainly 3 time. 8. Drying time peony after havesting was from 12 to 24 hours by briquet stove and 24 hours by ma­chine of hot wind, also dry method of peony was mixed briquet stove and hot wind machine.

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Removal of different anionic dyes from aqueous solution by anion exchange membrane

  • Khan, Muhammad Ali;Khan, Muhammad Imran;Zafar, Shagufta
    • Membrane and Water Treatment
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    • v.8 no.3
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    • pp.259-277
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    • 2017
  • Adsorption is a widely used technique for the removal of dyes from wastewaters by variety of adsorbents. In this work, the main focus is on the potential assessment of anion exchange membrane for the removal of different dyes using batch system and investigation of experimental data by applying various kinetic and thermodynamic models. The removal of anionic dyes i.e., Eosin-B, Eriochrome Black-T and Congo Red by anion exchange membrane BII from aqueous solution was carried out and effect of various parameters such as contact time, membrane dosage, temperature and ionic strength on the percentage removal of anionic dyes was studied. The experimental data was assessed by kinetic models namely pseudo-first-order, pseudo-second-order, Elovich liquid film diffusion, Bangham and the modified Freundlich models equation have been used to analyze the experimental data. These results indicate that the adsorption of these anionic dyes on BII follows pseudo-second-order kinetics with maximum values of regression coefficient (0.992-0.998) for all the systems. The adsorption of dyes was more suitable to be controlled by a liquid film diffusion mechanism. The adsorptive removal of dye Eosin-B and Eriochrome Black-T were decreased with temperature and thermodynamic parameters such as free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$) and entropy (${\Delta}S^o$) for adsorption of dyes on membrane BII were calculated at 298 K, 308 K and 318 K. The values of enthalpy and entropy were negative for EB and EBT representing that the adsorption of these dyes on BII is physiosorptive and exothermic in nature. Whereas the positive values of enthalpy and entropy for CR adsorption on BII, indicating that its adsorption is endothermic and spontaneous in nature. It is evident from this study that anion exchange membrane has shown good potential for the removal of dyes from aqueous solution and it can be used as adsorbent for dues removal on commercial levels.

The long-term centimeter variability of active galactic nuclei: A new relation between variability timescale and black hole mass

  • Park, Jongho;Trippe, Sascha
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.36.2-37
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    • 2016
  • We study the long-term radio variability of 43 radio bright AGNs by exploiting the data base of the University of Michigan Radio Astronomy Observatory (UMRAO) monitoring program. The UMRAO database provides high quality lightcurves spanning 25 - 32 years in time at three observing frequencies, 4.8, 8, and 14.5 GHz. We model the periodograms (temporal power spectra) of the observed lightcurves as simple power-law noise (red noise, spectral power $P(f){\propto}f^{-{\beta}}$ using Monte Carlo simulations, taking into account windowing effects (red-noise leak, aliasing). The power spectra of 39 (out of 43) sources are in good agreement with the models, yielding a range in power spectral index (${\beta}$) from ${\approx}1$ to ${\approx}3$. We find a strong anti-correlation between ${\beta}$ and the fractal dimension of the lightcurves, which provides an independent check of the quality of our modelling of power spectra. We fit a Gaussian function to each flare in a given lightcurve to obtain the flare duration. We discover a correlation between ${\beta}$ and the median duration of the flares. We use the derivative of a lightcurve to obtain a characteristic variability timescale which does not depend on the assumed functional form of the flares, incomplete fitting, and so on. We find that, once the effects of relativistic Doppler boosting on the observed timescales are corrected, the variability timescales of our sources are proportional to the black hole mass to the power of ${\alpha}=1.70{\pm}0.49$. We see an indication for AGNs in different regimes of accretion rate, flat spectrum radio quasars and BL Lac objects, having different scaling relations with ${\alpha}{\approx}1$ and ${\approx}2$, respectively. We find that modelling the periodograms of four of our sources requires the assumption of broken powerlaw spectra. From simulating lightcurves as superpositions of exponential flares we conclude that strong overlap of flares leads to featureless simple power-law periodograms of AGNs at radio wavelengths in most cases (The paper is about to be submitted to ApJ).

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Survey on the Incidence of Homeless Pulmonary Tuberculosis Infection Rate through Chest X-ray Examination (흉부 X-선 검사를 통한 노숙인 폐결핵 감염률 현황조사)

  • Kim, Mi-Young;Shin, Sung-Rae;Ryu, Young-Hwan;Lim, Hwan-Yeal
    • Journal of Radiation Industry
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    • v.10 no.4
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    • pp.249-255
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    • 2016
  • This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu findings's current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confirms the physician radiology, when sputum examination primarily chromatic findings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confirmed case result of checking whether there is a difference due to risk factors(Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (${\chi}^2=0.276$, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (${\chi}^2=9.414$, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specific location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

Characteristics of Road Weather Elements and Surface Information Change under the Influence of Synoptic High-Pressure Patterns in Winter (겨울철 고기압 영향에서 도로 위 기상요소와 노면정보 변화 특성에 관한 연구)

  • Kim, Baek-Jo;Nam, Hyounggu;Kim, Seon-Jeong;Kim, Geon-Tae;Kim, Jiwan;Lee, Yong Hee
    • Journal of Environmental Science International
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    • v.31 no.4
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    • pp.329-339
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    • 2022
  • Better understanding the mechanism of black ice occurrence on the road in winter is necessary to reduce the socio-economic damage it causes. In this study, intensive observations of road weather elements and surface information under the influence of synoptic high-pressure patterns (22nd December, 2020 and 29th January, and 25th February, 2021) were carried out using a mobile observation vehicle. We found that temperature and road surface temperature change is significantly influenced by observation time, altitude and structure of the road, surrounding terrain, and traffic volume, especially in tunnels and bridges. In addition, even if the spatial distribution of temperature and road surface temperature for the entire observation route is similar, there is a difference between air and road surface temperatures due to the influence of current weather conditions. The observed road temperature, air temperature and air pressure in Nongong Bridge were significantly different to other fixed road weather observation points.

Food Source Analysis of Rattus norvegicus, a Coinhabitant of Marine Birds in South Korea

  • Kang, Jihyun;Cha, Hyoun-Gi;Shin, Hyun Chul;Lee, Yunkyong;No, Doory;Kim, Wooyoung;Eum, Soon Jae
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.3
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    • pp.165-171
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    • 2022
  • The Chinese crested tern (Thalasseus bersteini) is one of the most globally endangered species, listed as "Critically Endangered (CE)" on the IUCN Red List, with only approximately 30-49 individuals surviving in the wild. Chinese crested terns were discovered to breed in South Korea for the first time in 2016 while conducting a census on uninhabited islands. The Ministry of Environment has declared the breeding habitat of the Chinese crested terns as "Specified Island" to protect this CE species. However, brown rats (Rattus norvegicus) inhabiting the breeding grounds of the Chinese crested terns and Black-tailed gulls may potentially pose a threat to the breeding of these avian species. Therefore, we conducted a study on the feeding behavior of brown rats involving stable isotope analysis to determine their food sources. Fecal analysis showed that brown rats mainly fed on plants, whereas they scarcely fed on animals, such as insects. In addition, the stable isotope analysis showed that the δ13C values of brown rats, insects, and Indian goosegrasses were approximately -16 to -11‰, whereas the δ13C value of Chinese crested terns that obtained their food from the marine ecosystem was approximately -22 to -18‰. Hence, we conclude that the source of carbon for brown rats on this island is the terrestrial ecosystem. We ruled out the possibility of any direct prey-predator interaction between the brown rat and the Chinese crested tern or Black-tailed gull.

An Experimental Study on the Flowability and Compressive Strength of Color Concrete Mixed with Pigments (안료를 첨가한 칼라콘크리트의 유동성 및 강도에 대한 실험적 연구)

  • Choi, Jae Jin;Hwang, Eui Hwan;Moon, Dae Joong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3A
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    • pp.547-553
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    • 2006
  • To know the effect of pigments on the material properties of color concrete, mortar and concrete tests were carried out by the using 5 kinds of pigment. The major component of red, yellow and black pigments was iron oxide and coloring component of blue and green pigments was copper phthalocyanine. Properties of mortar and concrete were some of difference according to adding ratio and kind of pigments. In case of using red, yellow and black pigments, setting time of concrete speeded a little and compressive strength was tendency to increase and slump or air content of concrete was same or decreased. On the other hand, in case of using green and blue pigments, compressive strength of concrete decreased largely because of the excessive air entrainment of surfactant and sump or air content of concrete increased highly. When the antifoaming agent was added to the color concrete mixed with green and blue pigments, compressive strength of concrete was improved and similar to that of concrete without pigment.

Study on Developing the Equipment of the Time Division System for Rehabilitation in People with Homonymous Hemianopia (동측성 반맹시 환자의 재활치료용 시분할 장치 개발에 관한 연구)

  • Seo, Jae-Myoung;Park, Gune-Ho;Heo, Min-Young;Jung, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.407-412
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    • 2014
  • Purpose: It is investigated whether the time division system can extend the field without diplopia for people with homonymous hemianopia. Methods: The time division system was manufactured by a modified mini fan and a black cardboard. In order to verify the effectiveness of the equipment, subjects with and without the equipment took part in the experiment to bisect the space and to recognize letters. Results: Subjects with and without the equipment showed +8.91 and +18.14 degrees in the experiment to bisect the space. In the experiment reading the letters and numbers with the equipment, there were 9 percentage point increase in $4{\times}4$ charts and 15 percentage point increase in $6{\times}6$ charts. It turned out that there was a remarkable improvement for the worst group for reading the charts. Conclusions: The time division system is effective in the mobility and orientation for people with homonymous hemianopia.