An On-Demand Routing Algorithm for Mobile Wireless Networks

Yan, Huai-Zhi,Ajith P.K,Park, Dong-Won,Joo, Gi-Ho 배재대학교 공학연구소 2005 공학논문집 Vol.7 No.1

An ad hoc network is a collection of wireless mobile nodes forming a temporary network without the centralized administration. Due to the limited transmission range of wireless work interface, multiple networks “hops” maybe needed for one node to exchange data with adjacent node. In recent years, a variety of new routing protocol about ad hoc network was developed. This paper presents a new routing protocol based on the Dynamic Source Routing which is not suitable for the high mobility ad hoc network. The Enhanced DSR adapts quickly to routing changes when node movement is frequent. When a trunk route is broken, this protocol will utilize the alternative route saved in the route to discovery quickly the new route. It improves the performance of the existing DSR algorithm, so that the negative impacts from weakness of DSR are reduced.

롤러스케이트 선수의 운동상해발생과 예방에 대한 조사 연구

김동희,김도수,채양석,이하얀,김선호,조성채 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The study was intended to research the fact of roller skate players injury. For the study, kinds and parts of injuries, skills to be hurted, facility, injured time, cause, remedy, mental response and protecting were investigated through 182 roller skate players. The results were as follows : 1. The injury body part was showed that leg was the highest and followed by knee and ankle. 2. In the cause of injury was showed as follows: skills on corner work, bank track with concrete, 200m distance. 3. In the general cause of injury was showed: chronic fatigue by over training. 4. In the treatment and participation period after injury outbreak were showed: treatment period was toward the inside 1 week and participation to play during the treatment. 5. To the injury prevention players responded warm up, and cool down and mental-concentration were needed. Supervisor, coach and players responded knee protector wearing was needed in elementary school players and helmet-chin protector wearing in general players. The game rule revision was not necessary and the agree and disagree for ground unity to resemble. Almost players to be like concrete ground.

자외선 (UVB) 노출 증가에 대한 피부암 위해도 예측 모델의 적용

신동천,이종태,정용,강나경,양지연 한국환경독성학회 1996 환경독성보건학회지 Vol.11 No.1

A decrease in stratospheric ozone probably caused by chloroflurocarbons (CFCs) emissions, has been observed large parts of the globe. It is generally accepted that if ozone levels in the stratosphere are depleted, greater amounts of shortwave ultraviolet radiation-B (UVB) will reach the earth's surface, resulting in increased incidence of nonmelanoma skin cancer. In this study, we evaluated several mathematical models, such as a power and an exponential model, and a geometric model considering the surface area of a human body part and ages for the prediction of skin cancer incidence caused by exposure to the UVB radiation. These models basically estimated the risk of skin cancer based on those measurements of the local ozone in stratosphere and UVB. Both were measured at a part of Seoul with a Dobson ozone spectrometer and Robertson-Berger UV Biometer for 1995. As a result, we calculated the point estimation applying a biological amplification factor (BAF), UVB radiation and other factors. We used a Monte-Carlo simulation technique with assumption on the distribution of each considered factor. The sensitivity analysis of model by there components conducted using Gaussian sensitivity method. The annual integral of UVB radiation was 2275 MED (minimal erythema dose)/yr. Also, an estimate of the annual amount of UVB reaching the earth's surface at a korea's latitude and altitude was 3328 MED/yr. The values of the radiation amplification factor (RAF) were ranged from 0.9 to 1.5 in Seoul. To give the effective factors required to model the prediction of skin cancer incidence caused by exposure to the UVB radiation in Korea, we studied the pros and cons of above mentioned models with the application of those parameters measured in Seoul, Korea.

알데히드탈수소효소 2(ALDH2) 및 CYP2E1 유전자 다형성에 따른 요중 뮤콘산 농도와 요중 8-hydroxydeoxyguanosine과의 관련성

김용대,강종원,엄상용,장연위,김성훈,김은영,이철호,문재동,김헌 대한산업의학회 2007 대한직업환경의학회지 Vol.19 No.2

Life Science : Evaluation of physicochemical properties, skin permeation and accumulation profiles of salicylic acid amide prodrugs as sunscreen agent

( Yi Dong Yan ),( Jun Ho Sung ),( Dong Won Lee ),( Jung Su Kim ),( Eun Mi Jeon ),( Dae Duk Kim ),( Dong Wuk Kim ),( Jong Oh Kim ),( Ming Guan Piao ),( Dong Xun Li ),( Chul Soon Yong ),( Han Gon Choi ) 영남대학교 약품개발연구소 2012 영남대학교 약품개발연구소 연구업적집 Vol.22 No.0

Various amide prodrugs of salicylic acid were synthesised, and their physicochemical propertiesincluding lipophilicity, chemical stability and enzymatic hydrolysis were investigated. In vivo skinpermeation and accumulation profiles were also evaluated using a combination of common permeationenhancing techniques such as the use of a supersaturated solution of permeants in an enhancer vehicle, a lipophilic receptor solution, removal of the stratum corneum and delipidisation of skin. Their capacity factor values were proportional to the degree of carbon-carbon saturation in the side chain. All these amides were highly stable in acetonitrile and glycerine. Amide prodrugs were converted tosalicylic acid both in hairless mouse liver and skin homogenates. N-dodecyl salicylamide (C12SM) showed the lowest permeation of salicylic acid in skin compared to the other prodrugs, probably due to its low aqueous solubility. It had a high affinity for the stratum corneum and its accumulation was restricted to only the uppermost layer of skin. Thus, this amide prodrug could be a safer topicalsunscreen agent with minimum potential for systemic absorption.ⓒ2011 Elsevier B.V.All rights reserved.

Cucumber Growth and Nitrogen Uptake as Affected by Solution Temperature and NO₃^-:NH₄⁺ Ratios during the Seedling

Yan, Qiu-Yan,Duan, Zeng-Qiang,Li, Jun-Hui,Li, Xun,Dong, Jin-Long Korean Society of Horticultural Science 2013 원예과학기술지 Vol.31 No.4

The effect of solution temperature and nitrogen form on cucumber (Cucumis sativus L.) growth, photosynthesis and nitrogen metabolism was investigated in hydroponic culture. Cucumber plants were grown for 35 days in a greenhouse at three constant solution temperatures ($15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$) within a natural aerial temperature ($15-30^{\circ}C$). Four nitrate:ammonium ($NO{_3}^-:NH{_4}^+$) ratios (10:0, 8:2, 5:5, and 2:8 $mmol{\cdot}L^{-1}$) at constant nitrogen (N) concentration of $10mmol{\cdot}L^{-1}$ were applied within each solution temperature treatment. Results showed an increasing solution temperature enhanced plant growth (height, dry weight, and leaf area) in most N treatments. Dry weight accumulation was greatest at the 10:0 $NO{_3}^-:NH{_4}^+$ ratio in the $15^{\circ}C$ solution, the 5:5 ratio in the $20^{\circ}C$ solution and the 8:2 ratio in the $25^{\circ}C$ solution. Photosynthetic rate (Pn) response to solution temperature and $NO{_3}^-:NH{_4}^+$ ratio was similar to that of plant growth. Probably, the photosynthate shortage played a role in the reduced biomass formation. Increasing solution temperature enhanced the nitrate reductase (NR) activity, and further reduced shoots nitrate content. Our results indicate that the optimal ratio of nitrate to ammonium that promotes growth in hydroponic cucumber varies with solution temperature.

Don Quijote y La dignidad del hombre

( Yan Sheng Dong ) 한국스페인어문학회 2006 스페인어문학 Vol.0 No.41

A pesar de su locura y de todas las peripecias que le han puesto en las situaciones mas grotescas y humillantes, es curioso que don Quijote nunca haya perdido la compostura. ¿Acaso Cervantes no ha querido insinuarnos la importancia de la dignidad del hombre? Efectivamente hemos podido atisbar entre lineas de su inmortal obra su exhortacion en este sentido a traves de la figura de don Quijote. La obtencion y la salvaguardia de la dignidad del hombre cobra especial significado cuando ella esta expuesta hoy en dia a una amenaza globalizante.

RESEARCH ARTICLE : Development of flurbiprofen-loaded nanoparticles with a narrow size distribution using sucrose

( Dong Hoon Oh ),( Yi Dong Yan ),( Dong Wuk Kim ),( Jong Oh Kim ),( Chul Soon Yong ),( Han Gon Choi ) 영남대학교 약품개발연구소 2014 영남대학교 약품개발연구소 연구업적집 Vol.24 No.0

Objective: A novel flurbiprofen-loaded nanoemulsion which gave uniform emulsion droplets with a narrow size distribution was previously reported to be prepared using membrane emulsification method. The purpose of this study is to develop a novel flurbiprofen-loaded nanoparticle with a narrow size distribution and improved bioavailability. Method: The nanoparticle was prepared by solidifying nanoemulsion using sucrose as a carrier via spray drying method. Its physicochemical properties were investigated using SEM, DSC and PXRD. Furthermore, dissolution and bioavailability in rats were evaluated compared to a flurbiprofen-loaded commercial product. Results: The flurbiprofen-loaded nanoparticles with flurbiprofen/sucrose/surfactant mixture (1/20/2, weight ratio) gave good solidification and no stickiness. They associated with about 70,000-fold improved drug solubility and had a mean size of about 300 nm with a narrow size distribution. Flurbiprofen was present in a changed amorphous state in these nanoparticles. Moreover, the nanoparticles gave significantly shorter Tmax, and higher AUC and Cmax of the drug compared to the commercial product (p<0.05). In particular, they showed about nine-fold higher AUC of the drug than did the commercial product. Conclusion: These flurbiprofen-loaded nanoparticles prepared with sucrose by the membrane emulsification and spray drying method would be a potential candidate for orally delivering poorly water-soluble flurbiprofen with enhanced bioavailability.

Hydrogels with diffusion-facilitated porous network for improved adsorption performance

Yan-yan Pei,Dong-mei Guo,Qing-da An,Zuo-yi Xiao,Shangru Zhai,Bin Zhai 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.12

Porous alginate-based hydrogel beads (porous ABH) have been prepared through a facile and sustainable template-assisted method using nano-calcium carbonate and nano-CaCO3 as pore-directing agent for the efficient capture of methylene blue (MB). The materials were characterized by various techniques. The sorption capacities of ABH towards MB were compared with pure sodium alginate (ABH-1:0) in batch and fixed-bed column adsorption studies. The obtained adsorbent (ABH-1:3) has a higher BET surface area and a smaller average pore diameter. The maximum adsorption capacity of ABH-1:3 obtained from Langmuir model was as high as 1,426.0mg g1. The kinetics strictly followed pseudo-second order rate equation and the adsorption reaction was effectively facilitated, approximately 50minutes to achieve adsorption equilibrium, which was significantly shorter than that of ABH-1:0. The thermodynamic parameters revealed that the adsorption was spontaneous and exothermic. Thomas model fitted well with the breakthrough curves and could describe the dynamic behavior of the column. More significantly, the uptake capacity of ABH-1:3 was still higher than 75% of the maximum adsorption capacity even after ten cycles, indicating that this novel adsorbent can be a promising adsorptive material for removal of MB from aqueous solution under batch and continuous systems.

Cr(VI) Resistance and Removal by Indigenous Bacteria Isolated from Chromium-Contaminated Soil

( Dong Yan Long ),( Xian Jin Tang ),( Kuan Cai ),( Guang Cun Chen ),( Chao Feng Shen ),( Ji Yan Shi ),( Ling Gui Chen ),( Ying Xu Chen ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.8

The removal of toxic Cr(VI) by microorganisms is a promising approach for Cr(VI) pollution remediation. In the present study, four indigenous bacteria, named LY1, LY2, LY6, and LY7, were isolated from Cr(VI)-contaminated soil. Among the four Cr(VI)-resistant isolates, strain LY6 displayed the highest Cr(VI)-removing ability, with 100 mg/l Cr(VI) being completely removed within 144 h. It could effectively remove Cr(VI) over a wide pH range from 5.5 to 9.5, with the optimal pH of 8.5. The amount of Cr(VI) removed increased with initial Cr(VI) concentration. Data from the time-course analysis of Cr(VI) removal by strain LY6 followed first-order kinetics. Based on the 16S rRNA gene sequence, strain LY6 was identified as Pseudochrobactrum asaccharolyticum, a species that had never been reported for Cr(VI) removal before. Transmission electron microscopy and energy dispersive X-ray spectroscopy analysis further confirmed that strain LY6 could accumulate chromium within the cell while conducting Cr(VI) removal. The results suggested that the indigenous bacterial strain LY6 would be a new candidate for potential application in Cr(VI) pollution bioremediation.