• 한국염색가공학회지
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• 제20권5호
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• pp.1-6
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• 2008

3-(Hydroxyphenyl phosphinyl) propanoic acid (HPPA) has been one of the most commonly used durable flame retardant agents for polyethylene terephthalate (PET) for many years. We intended to explore the application of HPPA to cellulose fabrics as formaldehyde-free phosphorus based flame retardants (FRs) through green chemistry process. The flame retardancy of the flame-retardant treated cellulose fabrics were characterized by using inductively coupled plasma spectroscopy (ICP) and limiting oxygen index (LOI). Structural changes of the treated cellulose fabrics were carried out by thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. To enhance the flame retardancy of HPPA treated cellulose fibers, glycerol polyglycidyl ether (GPE), a crosslinking agent was employed. Both HPPA and GPE treated cotton fabric imparted an LOI value over 26.

• 컴퓨터교육학회논문지
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• 제5권2호
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• pp.21-28
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• 2002

본 논문에서는 기존의 분산 컴퓨팅 시스템의 결합 포용 기법에 멀티 에이전트의 개념을 도입하여 운영체제에 독립적인 에이전트를 이용한 회복기법을 제안한다. 기존의 복귀회복기법들은 운영체제의 관리하에서 결함 발생 시 회복에 관련된 동기화를 수행하는데, 이는 전체 분산 컴퓨팅 시스템의 성능을 저하시키는 원인이 되었다, 이러한 문제점을 해결하기 위해 본 논문에서는 프로세스의 회복을 담당할 회복 에이전트, 결함 포용 규칙과 정보를 유지 관리하는 정보 에이전트, 전체 에이전트간의 통신 기능을 담당할 조정 에이전트를 정의 및 설계하고 회복 에이전트를 이용한 회복 알고리즘을 제안한다. 그리고 코바 환경에서 자바와 에이전트 통신 언어를 이용하여 제안한 회복 알고리즘을 실험하였다. 분산 컴퓨팅 시스템에서 회복 에이전트의 도입은 결함 발생 프로세스의 결함 회복 작업을 어플리케이션 계층과 독립적인 별도의 계층으로 계층화하여 결함 포용을 위한 메카니즘의 이식성 증대 및 확장성 증대를 가져온다.

• 한국정보통신학회논문지
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• 제11권10호
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• pp.1873-1879
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• 2007

P2P 서비스를 이용하는 이동 단말의 증가 및 응용 분야 확산에 따라 이동 에이전트 기술이 P2P에 적용되어 다양한 분야에 혁신적인 서비스를 제공하고 있다. 그러나 이동 에이전트의 자유로운 이동성은 웜과 유사하게 동작하기 때문에 악의적인 공격자의 공격에 따라 빠르게 오염되는 문제가 제기되었지만 현재로서는 근본적인 해결책이 전무한 상황이다. 본 논문에서는 구조적 인 P2P 환경에서 이동 에이전트의 안전성 검증을 제공하는 STAS(Security Tracking and Auditing Server) 시스템을 제안하였다. 이동 에이전트는 피어를 경유한 후 STAS에게 결과값을 전송함으로 보안감사 및 무결성을 검증받고, 이동 에이전트 생성자는 STAS로부터 최종 결과값을 획득한다. 이러한 방법을 통해서 이동 에이전트의 안전성 검증과 그 수행에 따라 발생할 이동 단말의 부하를 최소화할 수 있다.

• Mycobiology
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• 제36권1호
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• pp.13-18
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• 2008

Eight distinct bacteria were isolated form diseased mycelia of the edible mushroom, Pleurotus eryngii. 16S rDNA sequence analysis showed that the isolates belonged to a variety of bacterial genera including Bacillus (LBS5), Enterobacter (LBS1), Sphingomonas (LBS8 and LBS10), Staphylococcus (LBS3, LBS4 and LBS9) and Moraxella (LBS6). Among them, 4 bacterial isolates including LBS1, LBS4, LBS5, and LBS9 evidenced growth inhibitory activity on the mushroom mycelia. The inhibitory activity on the growth of the mushroom fruiting bodies was evaluated by the treatment of the bacterial culture broth or the heat-treated cell-free supernatant of the broth. The treatment of the culture broths or the cell-free supernatants of LBS4 or LBS9 completely inhibited the formation of the fruiting body, thereby suggesting that the inhibitory agent is a heat-stable compound. In the case of LBS5, only the bacterial cell-containing culture broth was capable of inhibiting the formation of the fruiting body, whereas the cell-free supernatant did not, which suggests that an inhibitory agent generated by LBS5 is a protein or a heat-labile chemical compound, potentially a fungal cell wall-degrading enzyme. The culture broth of LBS1 was not inhibitory. However, its cell-free supernatant was capable of inhibiting the formation of fruiting bodies. This indicates that LBS1 may produce an inhibitory heat-stable chemical compound which is readily degraded by its own secreted enzyme.

• 한방안이비인후피부과학회지
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• 제23권2호
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• pp.27-40
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• 2010

Background and Objective : Increasing interest in anti-aging and anti-wrinkling agents for the skin has triggered the recent outflow of researches and studies in this field. This study was designed to investigate the effects of bee venom on skin wrinkling and skin aging by testing the skin wrinkling, skin elasticity, trans-epidermal water loss (TEWL), free radical level, anti-oxidative agent level, and skin tissue after infusion of bee venom on hairless mouse. Materials and Methods : Fifteen hairless mice aged between 36~40 weeks were divided randomly into 3 Group; the Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group. The Bee Venom Syringe Group were injected subcutaneously with bee venom (0.1cc in total) using an insulin syringe on three spots in the lumbar spine (one spot on the center and two spots 1~2cm to the side bilaterally). The Bee Venom Needle Group were pricked with bee venom-smeared acupuncture needles on three longitudinal spots in the lumbar spine each 1cm apart, after which the needles were removed 10 minutes later. The Control Group did not receive any form of intervention. All procedures took place thrice a week for four weeks, during which the mice were allowed free access to water and fodder. The mice were measured and compared in the weight, skin wrinkling scale, skin elasticity, and TEWL before and after the experiment. After the experiment, blood samples were taken to measure the free radical and anti-oxidative agent level, and the skin tissue was sliced for examination. Data was analyzed using the SPSS program (ver 12.0). The ANOVA analysis was used to compare and contrast the three groups, and t-test for paired samples was used to evaluate skin-wrinkling before and after experiment. The cut-off p-value of significance was set at p<0.05. Results : 1. Administration of bee venom did not cause serious weight loss or gain. 2. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed a decrease in skin wrinkling scale after intervention. Especially, the Bee Venom Syringe Group showed a significant decrease (p<0.05). 3. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed an increase in skin elasticity. Especially, the Bee Venom Syringe Group showed a significant increase (p<0.05). 4. No significant change in TEWL was found in the mice in all the three groups before and after experiment. 5. Free radical level was normal in all 15 mice in all the three groups, and anti-oxidative agent was not significantly different across the three groups. 6. The Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group did not show any significant difference in the thickness of epidermis and dermis, infiltration of inflammatory cells, and skin wrinkling. The epidermis layer was relatively better preserved in the Bee Venom Syringe Group as compared to the Bee Venom Needle Group and the control group. Conclusion : Direct injection of bee venom on the hairless mouse using a syringe was found to improve wrinkling of the skin and increase skin elasticity but did not show effectiveness on skin dryness due to water loss. The bee venom appears to have suppressive effects on skin wrinkling, one of the symptoms of skin aging, through a process independent of suppression of free radicals or increase of anti-oxidative agent.

• Journal of Nutrition and Health
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• 제30권10호
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• pp.1132-1139
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• 1997

The effect of dietary taurine supplementation on plasma and hepatic lipid concentrations were evaluated in rats fed one of the following two cholesterol-free diets for 5 weeks ; a control diet(CD : cholesterol -free and taurine -fee diet) and a taurine supplemented diet(TSD : CD + 1.5% taurine). There were no significant differences in liver weight and cummulative body weight gains between the groups at the end of the experimental period .However, the liver weight to body weight ratio was significantly decreased (p<0.05) by dietary taurine supplementation. Plasma concentrations of total cholesterol , LDL-cholesterol and triglyceride were significantly reduced(37%, 26% and 53% respectively) in rats fed TSD compared to those fed CD. There were no significant differences in plasma free fatty acid and total phospolipid levels between the two groups. Feeding TSD to the rats significantly reduced their hepatic triglyceride concentration(43% decrease , p<0.001) but elevated their hepatic free fatty acid level(77% increase, p<0.001) as compared to the control rats. Liver cholesterol concentration was not significantly influenced by the dietary taurine supplementation. Dietary taurine supplementation significantly reduced the percentage of phosphatidylcholine and phosp-atidylethanolamine, but elevated the prospholipids in the liver homogenates as compared to the values for the CD rats. These results suggest the possible roles of taurine as a hypochlesterolmic and hypotriglyceride agent in rats fed a cholesterol-free diets.

• 한국보육지원학회지
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• 제19권2호
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• pp.119-141
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• 2023

Objective: This study aimed to investigate Pre-service early childhood teachers' perceptions and roles regarding young children's free play time. Methods: The study utilized the photovoice method and involved 21 pre-service early childhood teachers who expressed interest in participating. Participants were enrolled in an infants teaching methodology class in B city. The study involved four virtual meetings conducted via untact teams, and the automatic recordings of these meetings were transcribed for analysis. Results: The results revealed that pre-service early childhood teachers recognized young children's free play time as a period to enjoy full freedom, develop as the main agent of their lives, and express their imagination. Furthermore, pre-service early childhood teachers perceived their roles during young children's free play time as a specialist infant observer, a connector between play and learning, and a versatile supporter. Conclusion/Implications: The findings suggest the need for a systematic curriculum to provide pre-service early childhood teachers with a balanced perspective and awareness of the meaning of free play and teacher roles. The study highlights the importance of expanding pre-practice courses for observation of play and field-oriented curriculum for incumbent teachers.

• 약학회지
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• 제44권1호
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• pp.36-40
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• 2000

The photodegradation of pefloxacin, photolabile fluoroquinolone antibacterial agent, was studied. In the presence of $N_2$, photodegradation of pefloxacin was suppressed. The singlet oxygen and free radical generated in the reaction media proceeded photochemical reaction. The photodegradation of peflxacin was sensitized by benzophenone, a triplet state sensitizer.

• 유기물자원화
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• 제15권3호
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• pp.71-79
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• 2007

고분자 합성물질로 제조된 팽화제를 첨가하여 음식물쓰레기를 퇴비화하였다. 합성팽화제 첨가 효과는 초기 수분함량, 톱밥 첨가와 같은 퇴비화 조건이 적절할 때는 뚜렷이 관찰할 수 없었으나 수분함량이 70%이상이거나 식종퇴비 무첨가 등의 퇴비화 조건이 좋지 않은 상태에서 나타났다. 합성팽화제 첨가에 따른 긍정적 효과는 퇴비더미의 통기성이 개량되었기 때문으로 판단된다. 또한 합성팽화제를 첨가하면 일반적인 팽화제인 톱밥의 첨가량을 50% 정도 감소시킬 수 있는 것으로 나타났다. 그렇지만 합성팽화제는 수분을 조절히는 기능이 없기 때문에 음식물쓰레기의 수분함량을 적정 수준으로 조절하기 위해서는 건조, 탈수 등의 전처리 공정이 필요한 것으로 판단되었다. 또 톱밥을 첨가하지 않으면 퇴비 뭉침 현상에 나타나기 때문에 합성팽화제를 투입하더라도 일정량의 톱밥 첨가는 필요하였다.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.461-470
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• 2005

A dynamic supply chain that is composed of many different companies with different rent roles and interests allows free joining and secession. Buyers place orders simultaneously and manufacturers should compete each other for the orders. The purpose of our paper is how to find the optimal formation of supply chain ill a global viewpoint while allowing each member company to pursue his local goal The dynamic nature of supply chain formation causes the variation of cost depending on how many orders a manufacturer would accept. We propose a multi-agent based negotiation protocol that efficiently leads to the formation of optimal supply chain without giving up maximization of the individual profit in multi-agent environment of the make-to-order industry. The goal of the negotiation is to form a supply chain to minimize the overall sum of manufacturers' manufacturing cost, and earliness cost and tardiness cost based on SET model. We compare the negotiation protocol with Branch & Bound method. Finally, the validity and performance of buyer's negotiation has been tested experimentally.