• Proceedings of the SCSK Conference
• /
• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
• /
• pp.303-306
• /
• 2003

Indonesia is a tropical country having a temperature range of 25-35$^{\circ}C$ which can affect the skin and causes damages like aging. This aging process is due, at least, to free radical reactions. For this reason, many attempts had been done to find out creams containing natural antioxidant compound which have a potential of free radical scavenger. Kluwek, a fermented form of foot ball fruit or picung (Pangium edule.Reinw), had been proved to contain antioxidant compound in its methanol fraction oil to which antiaging cream was formulated. Stability evaluation was conducted for cream with Kluwek oil compared to base cream, including organoleptic (colour and odour), pH, viscosity, particle size, centrifugation test and flow characteristics either in room temperature (27$^{\circ}C$) or stress condition (4$^{\circ}C$ and 5$0^{\circ}C$) for 8 weeks continuously, and six times cycling test at 4$^{\circ}C$ and 5$0^{\circ}C$ every 24 hours. The results showed that cream with Kluwek oil and base cream were stable at temperature 27 and 4$^{\circ}C$, cycling test and centrifugation test, but not stable at 5$0^{\circ}C$. Free radical evaluation was done by Electron Spin Resonance and the result showed that cream with Kluwek oil had less free radicals compared to base cream.

• Korean Chemical Engineering Research
• /
• 제49권3호
• /
• pp.348-351
• /
• 2011

In this research, we developed a sensor system which can easily detect several chelating agents using polydiacetylene(PDA) vesicles. In comparison to other sensors, PDA based sensor has several advantages. First, detection method is much simpler and faster because it does not require any labeling step in the experiment procedure. Second, significant color-transition from blue to red based upon external stimulus allows us the detection by naked eyes. Finally, it is also possible to perform quantitative analysis of the concentration of the chelating agent by measuring the colorimetric response. In this paper, five types of chelating agents were used, including EDTA, EGTA, NTA, DCTA and DTPA. Among them, EDTA and DCTA triggered especially strong color-transition. In conclusion, this study has led to a successful development of a color transition-based PDA sensor system for easy and rapid detection of chelating agents.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• 제28권2호
• /
• pp.429-436
• /
• 2018

Electronic documents are efficient to be created and managed, but they are liable to lose their originality because copies are created during distribution and delivery. For this reason, various security technologies for electronic documents have been applied. However, most security technologies currently used are for document management such as file access privilege control, file version and history management, and therefore can not be used in environments where authenticity is absolutely required, such as confidential documents. In this paper, we propose a method to detect document forgery and tampering through analysis of file system without installing an agent inside the instance operating system in cloud computing environment. BubbleDoc monitors the minimum amount of virtual volume storage in an instance, so it can efficiently detect forgery and tampering of documents. Experimental results show that the proposed technique has 0.16% disk read operation overhead when it is set to 1,000ms cycle for monitoring for document falsification and modulation detection.

• Macromolecular Research
• /
• 제17권9호
• /
• pp.709-713
• /
• 2009

The aim of this study was to develop novel intestinal specific drug delivery systems with pH sensitive swelling and drug release properties. The carboxyl group of ibuprofen was converted to a vinyl ester group by reacting ibuprofen and vinyl acetate as an acylating agent in the presence of catalyst. The glucose-6-acrylate-1, 2, 3, 4-tetraacetate (GATA) monomer was prepared under mild conditions. Cubane-1, 4-dicarboxylic acid (CDA) linked to two 2-hydroxyethyl methacrylate (HEMA) group was used as the crosslinking agent (CA). Methacrylic-type polymeric prodrugs were synthesized by the free radical copolymerization of methacrylic acid, vinyl ester derivative of ibuprofen (VIP) and GATA in the presence of cubane cross linking agent. The structure of VIP was characterized and confirmed by FTIR, $^1H$ NMR and $^{13}C$ NMR spectroscopy. The composition of the cross-linked three-dimensional polymers was determined by FTIR spectroscopy. The hydrolysis of drug polymer conjugates was carried out in cel-lophane membrane dialysis bags, and the in vitro release profiles were established separately in enzyme-free simulated gastric and intestinal fluids (SGF, pH 1 and SIF, pH 7.4). The detection of a hydrolysis solution by UV spectroscopy at selected intervals showed that the drug can be released by hydrolysis of the ester bond between the drug and polymer backbone at a low rate. Drug release studies showed that increasing the MAA content in the copolymer enhances the rate of hydrolysis in SIP. These results suggest that these polymeric prodrugs can be useful for the release of ibuprofen in controlled release systems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• 제30권10호
• /
• pp.625-630
• /
• 2017

ZnS was chemically deposited as a buffer layer alternative to CdS, for use as a Cd-free buffer layer in $Cu(In_{1-x}Ga_x)Se_2$ (CIGS) solar cells. The deposition of a thin film of ZnS was carried out by chemical bath deposition, following which the structural and optical properties of the ZnS layer were studied. For the experiments, zinc sulfate hepta-hydrate ($ZnSO_4{\cdot}7H_2O$), thiourea ($SC(NH_2)_2$), and ammonia ($NH_4OH$) were used as the reacting agents. The mole concentrations of $ZnSO_4$ and $SC(NH_2)_2$ were fixed at 0.03 M and 0.8 M, respectively, while that of ammonia, which acts as a complexing agent, was varied from 0.3 M to 3.5 M. By varying the mole concentration of ammonia, optimal values for parameters like optical transmission, deposition rate, and surface morphology were determined. For the fixed mole concentrations of $0.03M\;ZnSO_4{\cdot}7H_2O$ and $0.8M\;SC(NH_2)_2$, it was established that 3.0 M of ammonia could provide optimal values of the deposition rate (5.5 nm/min), average optical transmittance (81%), and energy band gap (3.81 eV), rendering the chemically deposited ZnS suitable for use as a Cd-free buffer layer in CIGS solar cells.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• 제20권2호통권33호
• /
• pp.1-9
• /
• 2007

Objective : In this study, the ethanol extract from flowers of Lespedeza bicolor was investigated for their dermal bioactive properties related to cosmeceuticals such as depigmentation and radical scavenging effect. Results : The ethanol extract from flowers of Lespedeza bicolor showed considerable radical scavenging activity ($SC_{50}:\;10\;{\mu}g/ml$) and inhibited the production of nitric oxide (NO) in Raw 264.7 macrophages activated with the endotoxin lipopolysaccharide (LPS). Although the proliferation of B16/F10 cells was slightly decreased by the ethanol extract from flowers of Lespedeza bicolor at the concentration of $100\;{\mu}g/ml$, it did not appear necrosis. The ethanol extract from flowers of Lespedeza bicolor down-regulated melanin formation effectively. Methods : The free radical scavenging activity of Lespedeza bicolor was assayed in cell free systems using a stable free radical, 1,l-diphenyl-2-picrylhydrazyl (DPPH). Nitrite accumulated in culture medium was measured as an indicator of NO production using a Griess reaction. Cell viability was measured by MTT assay and melanin content was assessed using the method of Hosei with some modifications. Conclusions : These results suggest that the ethanol extract from flowers of Lespedeza bicolor is a potent depigmetation agent and it may be a candidate for antioxidant and anti-inflammatory agent.

• Korean Journal of Logic
• /
• 제21권3호
• /
• pp.373-393
• /
• 2018

Manipulation arguments purport to show that source freedom is incompatible with determinism. According to manipulation arguments, (1) intuitively, an agent manipulated in a certain manner to do A is not free, and (2) there is no significant difference between manipulation and determination. It follows that an agent determined to do A is not free. A compatibilist hard-line reply ('HR') denies (1), whereas a soft-line reply ('SR') denies (2). HR, which is arguably compatibilists' favorite, is assessed from the 'neutral stance.' HR turns out to fall short of adequately rejecting manipulation arguments. Recently Sartorio defends HR by claiming that (1) commits some sort of psychological fallacy. I argue that it does not work. I claim that SR is more promising. I examine the difference between intentional manipulation by design and ordinary determination. I argue that this difference suggests some determination scenario without intentional manipulation to which SR and manipulation arguments make different predictions, and that SR is better supported. Finally, incompatibilist objections are considered and replied.

• YAKHAK HOEJI
• /
• 제36권6호
• /
• pp.518-528
• /
• 1992

To determine the optimal conformation of sulfonylureas, the correlation between conformation and hypoglycemic activity of the two sulfonylureas of tolbutamide and chlorpropamide as hypoglycemic agent was studied using an empirical potential function (ECEPP/2) and the hydration shell model in the unhydrated and hydrated states. The conformational energy was minimized from several starting conformations with possible torsion angles in each molecule. The conformational entropy change of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecules in aqueous solution, the contribution of water-accessible volume of each group or atom in the lowest-free-energy conformation was calculated and compared each other. From comparison of the computed lowest-free-energy conformations of two sulfonylureas, it could be suggested that the hydration of sulfonylurea moiety is related to increase the hypoglycemic activity. From the calculation results, it was known that the conformational entropy is the major contribution to stabilize the low-free-energy conformations of two sulfonylureas in unhydrated state. Whereas, in hydrated state, the hydration free energy largely contributes to the total free energies of low-free-energy conformations of tolbutamide and conformational entropy contributes to stabilize the low-free-energy conformations of chlorpropamide. The torsion angles from phenyl ring to urea moiety of the low-free-energy conformations of the two sulfonylureas were shown the nearly regular trend. On the basis of these results, the conformation exhibiting the optimal hypoglycemic activity of sulfonylureas and the binding direction to pancreatic receptor site A could be predicted. Also, according to the side chain lengthening of urea moiety, tolbutamide showed various conformational change. Therefore, steric effect may be important factor in the interaction between sulfonylureas and the putative pancreatic receptor.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
• /
• pp.59-64
• /
• 2001

The robot soccer simulation game is a dynamic multi-agent environment. In this paper we suggest a new reinforcement learning approach to each agent's dynamic positioning in such dynamic environment. Reinforcement learning is the machine learning in which an agent learns from indirect, delayed reward an optimal policy to chose sequences of actions that produce the greatest cumulative reward. Therefore the reinforcement learning is different from supervised learning in the sense that there is no presentation of input pairs as training examples. Furthermore, model-free reinforcement learning algorithms like Q-learning do not require defining or learning any models of the surrounding environment. Nevertheless it can learn the optimal policy if the agent can visit every state- action pair infinitely. However, the biggest problem of monolithic reinforcement learning is that its straightforward applications do not successfully scale up to more complex environments due to the intractable large space of states. In order to address this problem. we suggest Adaptive Mediation-based Modular Q-Learning (AMMQL)as an improvement of the existing Modular Q-Learning (MQL). While simple modular Q-learning combines the results from each learning module in a fixed way, AMMQL combines them in a more flexible way by assigning different weight to each module according to its contribution to rewards. Therefore in addition to resolving the problem of large state effectively, AMMQL can show higher adaptability to environmental changes than pure MQL. This paper introduces the concept of AMMQL and presents details of its application into dynamic positioning of robot soccer agents.

• Proceedings of the Korea Society for Simulation Conference
• /
• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
• /
• pp.321-324
• /
• 2001

The robot soccer simulation game is a dynamic multi-agent environment. In this paper we suggest a new reinforcement learning approach to each agent's dynamic positioning in such dynamic environment. Reinforcement Beaming is the machine learning in which an agent learns from indirect, delayed reward an optimal policy to choose sequences of actions that produce the greatest cumulative reward. Therefore the reinforcement loaming is different from supervised teaming in the sense that there is no presentation of input-output pairs as training examples. Furthermore, model-free reinforcement loaming algorithms like Q-learning do not require defining or loaming any models of the surrounding environment. Nevertheless it can learn the optimal policy if the agent can visit every state-action pair infinitely. However, the biggest problem of monolithic reinforcement learning is that its straightforward applications do not successfully scale up to more complex environments due to the intractable large space of states. In order to address this problem, we suggest Adaptive Mediation-based Modular Q-Learning(AMMQL) as an improvement of the existing Modular Q-Learning(MQL). While simple modular Q-learning combines the results from each learning module in a fixed way, AMMQL combines them in a more flexible way by assigning different weight to each module according to its contribution to rewards. Therefore in addition to resolving the problem of large state space effectively, AMMQL can show higher adaptability to environmental changes than pure MQL. This paper introduces the concept of AMMQL and presents details of its application into dynamic positioning of robot soccer agents.