• Journal of Environmental Science International
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• v.16 no.9
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• pp.1099-1102
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• 2007

This paper presents eco-friendly planting method to overcome the problems of existing concrete retaining wall and gabion retaining wall, respectively, based on the examination on existing concrete and gabion retaining wall. Prior to doing this, proper design method was provided through pull out test. Planting method using gabion metal net and L shape green net retaining wall were compared and analyzed. According to this study, it is confirmed that reduction of construction period and economical profit in construction can be achieved by both manufacturing at the factory and self procurement at the job site as well as the use of metal net, which is applied as a substitution of existing strengthening material. For the effect of planting method, the use of L shape green net retaining wall shows superiority to environment-friendly gabion retaining wall in its ability to rootage and germination of the grass. The L shape green net retaining wall had excellent performance in helping rootage of grass and prevention of soil leakage, and even if raining period, remarkable damage of planting mat does not occur when planting mat is applied.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.83-97
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• 2013

This study was carried out to suggest an experimental base in selecting the drought resistance of plants. Adopting the natural drought method, this paper studies the drought resistance of 12 kinds of ground cover plants. focusing on analyzing the changes of relative water content on leaf, relative electric conductivity and chlorophyll content in 12 kinds of plants, and and the relation between soil water content under drought stress. The drought resistance of the plants were subject to laboratory and rooftop drought resistance treatments. The Logistic model of nonlinear regression analysis was used to evaluate the lethal time that were predicted with the range of 10.4~30.1d on roof top, and 19.5~39.0d on hothouse. The result shows that with the increase of stress time, relative water content and chlorophyll content on leaf were in a downward trend; the relative electric conductivity was upward tendency. Among 12 species of ground cover plants, exclude Pulsatilla koreana, Ainsliaea acerifolia were selected for rooftop plants because they showed resist drought strongly and took adaptive ability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4527-4547
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• 2018

Signcryption is a cryptographic primitive that provides authentication (signing) and confidentiality (encrypting) simultaneously at a lower computational cost and communication overhead. With the proposition of certificateless public key cryptography (CLPKC), certificateless signcryption (CLSC) scheme has gradually become a research hotspot and attracted extensive attentions. However, many of previous CLSC schemes are constructed based on time-consuming pairing operation, which is impractical for mobile devices with limited computation ability and battery capacity. Although researchers have proposed pairing-free CLSC schemes to solve the issue of efficiency, many of them are in fact still insecure. Therefore, the challenging problem is to keep the balance between efficiency and security in CLSC schemes. In this paper, several existing CLSC schemes are cryptanalyzed and a new CLSC scheme without pairing based on elliptic curve cryptosystem (ECC) is presented. The proposed CLSC scheme is provably secure against indistinguishability under adaptive chosen-ciphertext attack (IND-CCA2) and existential unforgeability under adaptive chosen-message attack (EUF-CMA) resting on Gap Diffie-Hellman (GDH) assumption and discrete logarithm problem in the random oracle model. Furthermore, the proposed scheme resists the ephemeral secret leakage (ESL) attack, public key replacement (PKR) attack, malicious but passive KGC (MPK) attack, and presents efficient computational overhead compared with the existing related CLSC schemes.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.6 no.1
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• pp.53-70
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• 1993

These experiments were conducted to investigate the effect of Taklee Hwangki Tang(THT) on inflammation. THT extract did not affected on the leakage of evans blue into peritoneal cavity and mouse paw edema induced by histamine, but decreased the cottom pellet granuloma formation. Using proliferation of Balb/c 3T3 fibroblast cell line as an in vitro model of granulation tissue formation, the ability of THT to stumulate cellular proliferation of fibroblast cells was investigated. When the cells were seeded at $1{\times}10^4$ cells/well, balb/c 3T3 cells are reached to the late expponential phase at 3rd day. Under the conditions established above, THT increased the proliferation of Balb/c 3T3 cells at concentration of $10^-,\;10^{-6}\;and\;10^{-5}g/ml$. The treatment of $10^{-6}g/ml$ of THT did not influence onthe NDA syntesis and proteinsynthesis of the cells. The $10\%$ serum from THT treated mice(500mg/kg/day for 4 days) increased the proliferation of Balb/c 3T3 fibroblast markedly, but decreased the DNA synthesis and protein sythesis of the cells. The results suggest that THT may be of practical therapeutic use at the period of the last in. flammation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.193-194
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• 2018

Common transistor has unipolar characteristics in accordance with the doping carriers and operation by the threshold voltage, which is related to the stability. It is required the low threshold voltage of transistors to increase the stability of devices. The sensing ability is about the detection of how low current, therefore there is difference between the low current and leakage current. This study researched the ambipolar characteristics of transistors with very low currents to define the difference between common n-type transistors with unipolar properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.467-471
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• 2001

DC accelerated aging characteristics of Pr$_{6}$O$_{11}$-based ZnO varistors, which are composed of ZnO+Pr$_{6}$O$_{11}$+CoO+Cr$_2$O$_3$+Dy$_2$O$_3$ ceramics were investigated with CoO content in the range of 0.5~5.0 mol%. The varistors doped with 1.0 mol% revealing maximum value(66.61) in the nonlinear exponent exhibited excellent stability, in which the variation rates of the varistor voltage, the nonlinear exponent and leakage current are -1.93%, -10.48%, and 288.79%, respectively, under DC accelerated aging stress, such as (0.85 V$_{1mA}$/115$^{\circ}C$/24h)+(0.90 V$_{1mA}$/12$0^{\circ}C$/24h)+(0.95 V$_{1mA}$/1$25^{\circ}C$/24h)+(0.95 V$_{1mA}$/15$0^{\circ}C$/24h). Next the varistors doped with 2.0 mol% exhibiting the nonlinear exponent of 47.39 showed high stability,ity,ability,ity,

• Journal of Power Electronics
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• v.17 no.3
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• pp.579-589
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• 2017

In this study a new high step-up dc-dc converter is presented. The operation of the proposed converter is based on the capacitor switching and coupled inductor with a single active power switch in its structure. A passive voltage clamp circuit with two capacitors and two diodes is used in the proposed converter for elevating the converter's voltage gain with the recovered energy of the leakage inductor, and for lowering the voltage stress on the power switch. A switch with a low $R_{DS}$ (on) can be adopted to reduce conduction losses. In the generalized mode of the proposed converter, to reach a desired voltage gain, capacitor stages with parallel charge and series discharge techniques are extended from both sides of secondary side of the coupled inductor. The proposed converter has the ability to alleviate the reverse recovery problem of diodes with circuit parameters. The operating principle and steady-states analyses are discussed in detail. A 40W prototype of the proposed converter is implemented in the laboratory to verify its operation.

• Convergence Security Journal
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• v.17 no.5
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• pp.71-76
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• 2017

Today, it is an information society where a large number of users access and view important data in a large number of information assets as needed. In this complexity, techniques related Identify Management are being applied, in order to verify authorized user access to important information assets and manage of history. But, the ability access to sensitive information using account has the disadvantage of being able to open the way for information to the attacker when it is hijacked. Thus, in this paper, we propose a secure Identify Management System that can control the use of accounts based on the attitude of the account holder, but also enhances the security and does not hinder the convenience.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.67-71
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• 2019

All countries, including Korea, are currently experiencing the effect of rapid climate change. As a result, the cultivation area of many crops including wheat is changing, or productivity is falling sharply. If enough nitrogen is present in the soil, the increase in atmospheric carbon dioxide due to the greenhouse effect can lead to increased photosynthesis of plants, resulting in increased productivity. By contrast, a low proportion of nitrogen in soil does not increase production, often leading to the use of nitrogen fertilizers to increase crop productivity: this causes serious environmental pollution due to the leakage of nitrogen fertilizers used by crops. Increasing the understanding of the molecular level of the plant nitrogen use efficiency mechanism may contribute to increased productivity of crops and reduced of environmental pollution by nitrogen. In Korea, cultivars have developed 35 kinds of wheat, such as 'keumgang' and 'Chokyeong', which can be used for specific purposes such as baking or noodles. In this study we investigate 'keumgang' and 'Chokyeong' in order to elucidate the mechanism of nitrogen use ability of wheat and contribute to the reduction of environmental pollution by providing guidelines for the proper use of nitrogenous fertilizer.

• Journal of radiological science and technology
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• v.42 no.5
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• pp.365-371
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• 2019

We have developed and applied a diagnostic Multi-Leaf Collimator (MLC) to optimized the X-ray field in medical imaging and the usefulness evaluated through the fusion of infrared image and X-ray image acquired by infrared camera. The hand and skull radiography with multi-leaf collimator(MLC) showed significant area dose reductions of 22.9% and 31.3% compared to ARC and leakage dose was compliant with KS A 4732. Also scattering doses of 50 cm and 100 cm showed a significant decrease to confirm the usefulness of MLC. It was confirmed that the fusion of infrared images with an adjustable degree of transparency was possible in the X-ray images. Therefore, fusion of anatomical information with physiological convergence is expected to contribute and improvement of diagnostic ability. In addition, the feasibility of convergence X-ray imaging and DITI devices and the possibility of driving MLC with infrared images were confirmed.