• Transactions of the Korean hydrogen and new energy society
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• v.16 no.1
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• pp.17-24
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• 2005

We experimented on growth in light and production of hydrogen and organic matters in dark fermentation by using C. reinhardtii. In the light, growth rate of C. reinhardtii following $CO_2$ fixation was proportional to consumption rate of nitrogen source. And the starch in cell was accumulated more when the period of culture was lengthened more. But the accumulation rate of starch in cell was decreased when the growth rate of cell become dull. In the dark fermentation, the production volume and production rate of hydrogen were the highest value in the mid exponential state among other states. The utilization efficiency of substrate was better in the early exponential state than other states. In production of organic matters, acetic acid didn't change remarkably and ethanol showed the highest value in early exponential state.

• Korean Journal of Microbiology
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• v.7 no.1
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• pp.1-9
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• 1969

Changes in the phosphorylation of Chlorella cells during the life cycle the aulotrophic and micotrophic synchronous culture were followed under the light and dark. 1. In the autotrophic culture of Chlorella the amounts of esterified phosphate compounds of the algal cell under the light increased during the growing period and decreased strikingly in the ripening period showing a peak at the $L_1$ i/-cell stage. 2. TRhe amount of total esterified phosphate compounds of the cell under the dark, however, decreased during the growing period and then kept fairly constnat during the ripening nad division periods showing the greates activity of the oxidative phosphorylation in the early growing stage. 3. It is presumed that the energy requirement of the dividing algal cell in the autotrophic culture is fulfilled prior to the nuclear division mostly by the photosynthetic phosphorylation. 4. In the mixotrophic culture, the amount of esterified phosphate compounds of the algal cells under the light increased during the growing period and decreased during the late ripening and early division periods showing a peak in the $L_2$-cell stage as in the case of the phosphorylation under the dark. 5. The phosphorylation of the fell grown in the glucose medium is more active under the dark than under the light in the stages of the growing and early ripening periods. 6. It is considered that the excess glucose in the algal cell not only promotes the oxidative phosphorylation but also inhibits the photosynthetic phosphorylation of the cell. 7. It is presumed that the energy requirement of the dividing algal cell in the glucose medium is fulfilled prior to the nuclear division by the combined action of oxidative and photosynthetic phosphorylation, mostly by the oxidative phosphorylation.

• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.107-117
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• 1996

We have studied the star forming activities and dust properties of Lynds 1251, a dark cloud located at relatively high galactic latitude. Eleven IRAS point sources identified toward Lynds 1251 are discussed. Estimate of stellar masses, and far-infrared lumnosities of the young stars associated with two prominent IRAS point sources imply that these are T-Tauri stars with masses smaller than $0.3 M_\bigodot$. The low dust temperature of 27 K and low ratio of FIR emission to hydrogen column density are probably due to the lack of internal heating sources. Presumably two low mass young stars do not have enough energy to heat up the dust and gas associated. The dust heating is dominated by the interstellar heating source, and the weaker interstellar radiation field can explain the exceptionally low dust temperatures found in Lynds 1251. The estimated dust mass of Lynds 1251 is just $\~1M_\bigodot$, or about 1/1000 of gas mass, which implies that there must be a substantial amount of colder dust. The infrared flux at $100{\mu}m$ is matching well with $^{13}CO$ peak temperature, while the $^{12}CO$ integrated intensity is matching with the boundary of dust emission. Overall, the dust properties of Lynds 1251 is similar to those of normal dark clouds even though it does have star forming activities.

• Smart Media Journal
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• v.11 no.10
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• pp.46-53
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• 2022

Today, due to the 4th industrial revolution and extensive R&D funding, domestic companies have begun to possess world-class industrial technologies and have grown into important assets. The national government has designated it as a "national core technology" in order to protect companies' critical industrial technologies. Particularly, technology leaks in the shipbuilding, display, and semiconductor industries can result in a significant loss of competitiveness not only at the company level but also at the national level. Every year, there are more insider leaks, ransomware attacks, and attempts to steal industrial technology through industrial spy. The stolen industrial technology is then traded covertly on the dark web. In this paper, we propose a system for detecting industrial technology leaks in the dark web environment. The proposed model first builds a database through dark web crawling using information collected from the OSINT environment. Afterwards, keywords for industrial technology leakage are extracted using the KeyBERT model, and signs of industrial technology leakage in the dark web environment are proposed as quantitative figures. Finally, based on the identified industrial technology leakage sites in the dark web environment, the possibility of secondary leakage is detected through the PageRank algorithm. The proposed method accepted for the collection of 27,317 unique dark web domains and the extraction of 15,028 nuclear energy-related keywords from 100 nuclear power patents. 12 dark web sites identified as a result of detecting secondary leaks based on the highest nuclear leak dark web sites.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.98-103
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• 2009

In this paper, we test the electrical resistance of flat wire in the PV module. normally solar cell has two kind of flat wire(inter connection ribbon and bus bar ribbon). we found the phenomenon that has a unbalance with resistance when we make a wiling between of string. So, we measurement the resistance of flat wire each other. and analysis of missmatch with resistance between flat wires on PV module. next to survey of IR picture on missmatch flat wire samples for analyze of missmatch with current in the wire. and we perform IR test with solar cell that has a connection with flat wire for test the effect of missmatch resistance on solar cell. Finally we perform the Dark I-V test for survey of effect by the unbalance of resistance. By the result of Dark I-V test, the series resistance of existing connection sample is large more then innovated connection sample.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.175-179
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• 2005

To develop a high efficiency plant regeneration system from in vitro cultures of strawberry, cv. Yeobong, petiole and leaf explants were cultured on MS basal medium containing a combination of 0.5 mg/L IBA and 3.2 mg/L kinetin or zeatin or benzyl amino purine (BAP) for 6 weeks, and leaf explants with dark pretreatment for a week ($T_1$), 2 weeks ($T_2$), and 4 weeks ($T_3$) were cultured on medium supplemented with 0.5 mg/L IBA and 3.2 mg/L zeatin under 16 hr photoperiod for 6 weeks. Shoot organogenesis was observed from the greenish calli containing minimal anthocyanin formed at proximal cutting edges of the leaf explant (57%) when cultured adaxial side on the medium, whereas was directly formed from a cutting edges of petiole explant (6.3%). Frequency of callus formation and shoot organogenesis at large size of leaf explant ($1.0{\sim}1.5\;cm^2$) was higher than small size ($0.5{\sim}1.0\;cm^2$), and dark pretreatment significantly improved the frequency of leaf explants that produced calli and shoots. The maximum frequency (87%) for shoot organogenesis was obtained from the leaf explants that transferred to a 16 hr photoperiod condition after the initial 4 weeks dark period. The improved frequency (87%) in comparision with control without dark pretreatment (27%). When the shoots were transferred to 1/2 MS basal medium, formed roots with 20 d of culture. The rooted plants were subsequently transferred to the pots and to the field.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.49.3-49.3
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• 2020

I will give an overview of the recent work in deriving cosmological constraints from deep learning methods applied to the large scale distribution of galaxies. I will specifically highlight the success of convolutional neural networks in linking the morphology of the large scale matter distribution to dark energy parameters and modified gravity scenarios.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.5
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• pp.276-283
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• 2017

A polysilicon-based metal-semiconductor-metal (MSM) photodetector was fabricated by means of our new methods. Its photoresponse characteristics were analyzed to see if it could be applied to a sensor system. The processes on which this study focused were an alloy-annealing process to form metal-polysilicon contacts, a post-annealing process for better light absorption of as-deposited polysilicon, and a passivation process for lowering defect density in polysilicon. When the alloy annealing was achieved at about $400^{\circ}C$, metal-polysilicon Schottky contacts sustained a stable potential barrier, decreasing the dark current. For better surface morphology of polysilicon, rapid thermal annealing (RTA) or furnace annealing at around $900^{\circ}C$ was suitable as a post-annealing process, because it supplied polysilicon layers with a smoother surface and a proper grain size for photon absorption. For the passivation of defects in polysilicon, hydrogen-ion implantation was chosen, because it is easy to implant hydrogen into the polysilicon. MSM photodetectors based on the suggested processes showed a higher sensitivity for photocurrent detection and a stable Schottky contact barrier to lower the dark current and are therefore applicable to sensor systems.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.426-433
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• 1995

Effect of boron in GaAs have been investigated by photo induced current transient spectroscopy(PICTS). The starting material was undoped liquid encapsulated Czochralski(LEC) semi insulating GaAs and boron ion implantation at 150keV energy was conducted with dose of 10$\^$12/ and 10$\^$13/ions/cm$\^$2/. In ion implanted samples, the peaks related arsenic vacancy(V$\_$As/) were decreased but complex lattice defect was increased with annealing temperature. U band was observed at ion implanted(10$\^$13/ ions/cm$\^$2/) and thermally treated(550.deg. C) sample. More negative peak was detected after annealing at temperature between 600 and 700.deg. C. The measurement of dark current showed that the formation of B$\_$GA/-V$\_$As/, complex defect and complex lattice defect by ion implantation were a reasonable explanation for the decrease in dark current.