• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.32-32
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• 2023

Cadmium and salt exposure to crops is considered vulnerable for production as well as consumption. To address these challenges, the current study aimed to mitigate the toxicity induced by salt and cadmium in soybean plants through the application of bacterial strain Bacillus safensis KJW143 isolated from the rhizosphere of oriental melon..The bioassay analysis revealed that KJW143 is a highly salt-tolerant and cadmium-resistant (Cd) strain with an innate ability to produce melatonin, gibberellin (GA3), Indole-3-Acetic Acid (IAA), and organic acids (i.e., acetic, succinic, lactic, and propionic acids). Soybean plants at 20 days old were treated with KJW143 in a different form (pellet, broth, and together) and their effect on plant performance was investigated. Inoculation with KJW143enhanced plant biomass and growth attributes in soybean plants compared to the control (non-treated). In particular, we observed that only pellet-treated showed 65%, 27.5%, and 28.7% increase in growth (shoot fresh weight) compared to broth, broth with pellet, and control. In addition, bacterial strain KJW143 treatment (only pellet) modulated the physiochemical apparatus of soybean plants by increasing glucose (390%), arabinose (166%), citric acid (22.98%) and reducing hydrogen peroxide (29.7%), catalase (32.1%), salicylic acid (25.6%) compared to plants with combined stressed plants (cd and salinity). These findings suggest that bacterial strain KJW143 could be usedas a biofertilizer to minimize the probable risk of heavy metal and salinity stress on crops.

• BMB Reports
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• 제40권5호
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• pp.644-648
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• 2007

Exposure of algae or plants to irradiance from above the light saturation point of photosynthesis is known as high light stress. This high light stress induces various responses including photoinhibition of the photosynthetic apparatus. The degree of photoinhibition could be clearly determined by measuring the parameters such as absorption and fluorescence of chromoproteins. In cyanobacteria and red algae, most of the photosystem (PS) II associated light harvesting is performed by a membrane attached complex called the phycobilisome (PBS). The effects of high intensity light (1000-4000 ${\mu}mol$ photons $m^{-2}s^{-1}$) on excitation energy transfer from PBSs to PS II in a cyanobacterium Spirulina platensis were studied by measuring room temperature PC fluorescence emission spectra. High light (3000 ${\mu}mol$ photons $m^{-2}s^{-1}$) stress had a significant effect on PC fluorescence emission spectra. On the other hand, light stress induced an increase in the ratio of PC fluorescence intensity of PBS indicating that light stress inhibits excitation energy transfer from PBS to PS II. The high light treatment to 3000 ${\mu}mol$ photons $m^{-2}s^{-1}$ caused disappearance of 31.5 kDa linker polypeptide which is known to link PC discs together. In addition we observed the similar decrease in the other polypeptide contents. Our data concludes that the Spirulina cells upon light treatment causes alterations in the phycobiliproteins (PBPs) and affects the energy transfer process within the PBSs.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.159-162
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• 2001

Plant stress incurred by flooding was studied in terms of oxidative stress, using greened rice seedlings subjected to a complete submergence followed by re-exposure to air under illumination ($30W/m^2$). It appeared that shoot tissues of the seedlings suffered oxygen deficiency during the flooding treatment, pertinent to the general concept. Interestingly enough, however, membrane peroxidation in shoots was enhanced by the submergence, as assessed by the content of 2-thiobarbituric acid-reactive substances (TBARS), and the re-aeration resulted in a rapid reduction of TBARS content. Such pattern of response was also seen in the change in the steady state level of $H_2O_2$. In contrast, superoxide dismutase and glutathione reductase that are involved in the detoxifying processes of superoxide in plant cells were significantly activated only during the re-aeration. These results allowed us to suggest the followings as a working hypothesis. Photorespiration-linked production of $H_2O_2$ may largely contribute to the increase in $H_2O_2$ level as well as TBARS production in shoots during the submergence. An abrupt re-supply of $CO_2$ by the re-aeration brings the photosynthetic apparatus back to full operation, suppressing photorespiration and probably causing a momentary, excess formation of superoxide and its dismutation product through side reaction, which gives rise to activating substrate-inducible antioxidative enzymes.

• 한국정보과학회논문지:시스템및이론
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• 제28권10호
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• pp.491-498
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• 2001

컴퓨터 그래픽스 분야에서 물체나 장면을 실제 사진처럼 표현할 목적으로 표변 반사 특성에 고나한 많은 연구가 이루어져왔다. 본 논문은 물체의 표면 반산 특성을 구하기 위한 특별한 장비나 복잡한 기하학적인 정보를 필요로 하지 않는 광원 모델링 기법을 제시한다. 이 기법은 영상의 픽셀 밝기정보가 아닌. 카메라로 들어오는 실제 밝기를 나타내는 라디안스 정보를 이용하여 물체 표면의 반사 특성(BRDF)를 측정하는것이 특징이다. 본 논문에서 제안한 광원 모델링을 통하여 다양한 광원에서의 사실적인 장면을 복원할 수 있을 뿐만 아니라 다양한 광원의 조작과 카메라 센서의 노출시간을 자류롭게 조절하는것이 가능하다.

• 한국안전학회지
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• 제25권1호
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• pp.27-31
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• 2010

It is a well known fact that the LCD and Semiconductor Devices are a central part of IT industry which is important in the present and the future. But the biggest problem of Semiconductor and LCD manufacturing is maintaining a cleaning room environment. For this reason, the soft X-ray type Ionizer was used as the electrostatic reducer device, which protects damage of the product against electrostatic discharge in the manufacturing process. Therefore it is a essential important factor during Semiconductor and LCD production process. But the soft X-ray has a intrinsic problem with harmful to human being in case of soft X-ray exposure. That's reason we have the research to solve above problem and made an apparatus that it was covered with shielding structure to protect X-ray radiation to outside. And besides, it has a possibility to eliminate the charged electrostatic in the narrow space through the slot for Ion emissions with dual soft X-ray sources on the both side. It is also not make the particles from itself when it has been operated.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.51-54
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• 2008

A novel stereolithography method using evanescent light has been proposed as a means to realize 100-nanometer resolution. An in-process measurement system with high accuracy has been introduced to the nanostereolithography apparatus. Specifically, an optical microscopic system was developed to monitor the exposure process and a confocal positioning system was established to improve the longitudinal positioning accuracy in the layer-by-layer process. A high-power objective lens, a tube lens, and a charge coupled device (CCD) were included in the optical microscopic system, whereas a laser, a high-power objective lens, a piezoelectric (PZT) stage, a condenser lens, a pinhole, and a photomultiplier (PMT) made up the confocal microscopic system. Two verification experiments were conducted, and the results indicated that the optical microscopic system had a horizontal resolution of 200 nm and that the confocal positioning system provided a depth resolution of 30.8 nm. These results indicate that nanostereolithography can be successfully performed with this system.

• 한국정밀공학회지
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• 제19권3호
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• pp.152-159
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• 2002

SLA (Stereolithography Apparatus) it a process used to rapidly produce polymer components directly from a computer representation of the part. Though SLA is being recognized as an innovative technology, it still cannot be used to fully practical application since it lacks of dimensional accuracy compared to conventional process. If the shrinkage were perfectly uniform and no distortion took place, excellent part accuracy could still be achieved through and appropriate scaling factor when generating the build file. However, in certain geometries involving intersecting thick and thin sections, nonuniform retrain shrinkage becomes the engine of part distortion. In order to improve the part accuracy of SLA, this paper evaluates how largely each parameter of SLA contributes to the part accuracy and estimates the optimal set of parameter which minimizes the dimension error of the test part, "Slab (100mm$\times$100mm$\times$2mm)"and "scale bar"part. Three control parameters such as critical exposure, generation depth and fill cure depth are used.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.949-961
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• 1997

To date, various clinical procedures have been used to restore periodontal apparatus destroyed by periodontal disease. And then, many experimental approaches have been proceeded to develop treatment methods to promote periodontal regeneration. Mechanical, chemical treatments to enhance the attachment of periodontal tissue cells as changing the physical properties of root surfaces, bone graft procedure, and treatments for guided tissue regeneration have been used for periodontal regeneration. However, recent studies have revealed that biologic factors such as growth factors promote biologic mechanism associated with periodontal regeneration. This study was done to enucleate how ELF stimulus affect the periodontal regeneration. We can have following conclusions from this experimental results. The influence of low frequency(ELF) electric stimulus (30Hz at $lO{\mu}A$) known to promote bone formation in vivo, was evaluated for its ability to affect bone cell function in vitro. After 12 hour exposure of ELF stimulus at most appropriate densities ($5{\times}10^4\;cells/cm^2$) to increase osteoblastic cells normally, rat calvarial cells were incubated for 60 hours were used in this study. We have found ELF stimulus suppress calvarial cell proliferation and the ability of protein synthesis, enhance the alkaline phosphatase activity significantly.

• 보존과학연구
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• 통권30호
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• pp.47-61
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• 2009

Cultural heritages are affected by various environmental factors. Main factors are temperature, humidity, light and indoor air pollutants such as ozone, nitrogen oxides. Especially humidity condition is very important. Low humidity condition can cause contraction and high humidity condition can lead to growth of microorganism. This study is conducted to appraise an applicability of the Humidity Indicator which is one of the simple method for humidity control. The Humidity Indicator shows the humidity conditions through color change. Therefore, photometer was used to correctly measure the color change of Humidity Indicator. As a result of lab test, Humidity Indicators was stabilized after one hour from en exposure in a certain humidity condition and the indicators indicated clear correlations between color changes of Humidity Indicators and humidity conditions. Some Humidity Indicators which had been selected through the lab tests were applied to preservation facilities of cultural heritages and the indicators indicated closed correlations with humidity conditions in indoor of facilities.

• Journal of Photoscience
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• 제5권2호
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• pp.53-61
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• 1998

Using a squash plant, a chilling-sensitive species, and a spinach plant, a chilling-resistant one, effects of chilling temperature on the photosynthetic machinery were studied in terms of chlorophyll fluorescence. When thylakoid membranes were isolated and subjected to incubation at different temperatures, spinach showed stable photosystem II activity at the low temperature side, in contrast to squash which showed quite severe inactivation at low temperature. When parameters of chlorophyll fluorescence were examined, chilling in darkness did not affect either Fv/Fm or photochemical and non-photochemical quenching, in both types of plants. However, chilling of squash plants under irradiance of medium intensity caused a specific decrease in Fv/Fm accompanied by a decline in energy-dependent quenching. Contrastingly, photosystem li of spinach plants were not much affected by light-chilling. When the pool size of zeaxanthin was examined after exposure to high light at different temperatures, squash plants was shown to have a much lower content of antheraxanthin + zeaxanthin, as compared to spinach plants, during low-temperature photoinhibition. These results suggest that chilling-sensitive plants have low capacity to dissipate excitation energy nonradiatively, when they are exposed to low-temperature photoinhibition, and, as a consequence, more vulnerable to photoinhibitory, damage to the photosynthetic apparatus.