• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.203-210
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• 2014

본 연구는 생산공정운영시 발생하는 담당자의 의사결정 지원을 위한 학습형 공정 의사결정 시스템 구축방법에 대한 것이다. 먼저 추출 및 누적된 각 공정 별 이력 데이터에서, 주요한 주요자원(Critical Resource)을 단계적 회귀법에 따라 선정한다. 선정된 주요자원을 독립변수로 취급하여 담당자의 의사결정 대상이 되는 공정운영 성과를 종속변수로 하는 회귀모형을 산출하고, 해당 주요자원으로 구성된 시뮬레이션 모형을 설계한다. 메타휴리스틱 방법을 통하여 의사결정 시점의 생산계획 및 목적에 대한 시뮬레이션 분석을 실행하고, 복수 대안 및 가능해(기대성과)를 산출한다. 각각의 대안에서 주요자원 별 회귀모형을 구성하는 분석 값을 회귀식에 대입하고, 여기에서 얻어지는 값과 시뮬레이션 분석에 의해 산출된 가능해 간의 비교를 통하여 그 차이가 가장 작은 대안을 최적대안으로 선정하고 실제 공정운영 의사결정에 반영하여 생산을 실시한다. 이때 발생하는 공정 이력 데이터들은 이후 의사결정을 위한 회귀모형에 피드백 된다.

• 공업화학
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• 제3권1호
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• pp.1-6
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• 1992

메탄올은 저급(低級) 탄소원(炭素源)의 활용(活用)이란 측면(側面)에서, 에너지 저장(貯藏) 운송(運送)이란 관점(觀點)에서 점점 관심(關心)을 끌고 있다. 특히 저급탄소원(低級炭素源)으로부터의 메탄올 합성기술(合成技術)은 이미 상업화(商業化)되어 있는 기술(技術)이기 때문에 더욱 현실적(現實的)인 기술(技術)로 대두되고 있다. 메탄올은 발전(發電), 도시(都市)가스, 화학원료(化學原料) 및 운송연료(運送燃料)로 저급(低級) 탄소원(炭素源)을 활용(活用)할 경우(境遇), 상호(相互) 연계(連繫)하는 매개체(媒介體)로 사용(使用)할 수 있으므로 이를 국익(國益) 차원(次元)에서 C1화학(化學) 기술(技術)을 통한 연계방안(連繫方案)을 기술(技術)하려고 시도하였다. 특히 이산화탄소(二酸化炭素)를 자연계(自然界)에서처럼 일종(一種)의 수소저장(水素貯藏) 수단(手段)으로 메탄올 합성(合成)에 이용(利用)함으로 지구온난화(地球溫暖化) 같은 환경문제(環境問題)를 줄이는 방안(方案)으로 제시(提示)했다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.113-118
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• 2006

The effects of dietary Rhus verniciflua Stokes supplementation (0%, 2%, 4% and 6%/feed) on meat color, water-holding capacity (WHC), lipid oxidation and fatty acid composition in m. longissimus from Hanwoo (Korean cattle) beef during refrigerated storage were investigated. The $L^*$, $a^*$, $b^*$ and $C^*$ values of 4% group were significantly (p<0.05) higher than those of the other groups for 7 days of storage. The $a^*$, $b^*$ and $C^*$ values declined gradually during storage in all of the groups and the decline was more rapid in control group. The metmyoglobin (%) was significantly (p<0.05) increased during storage time in all of the groups, but the 4% group had a lower rate of metmyoglobin accumulation during storage. WHC was significantly (p<0.05) higher in the 2% and 4% groups than in the other groups. The TBARS (thiobarbituric acid reactive substances) value of day 0 was not significantly (p>0.05) different among 4 diet conditions, but the TBARS value after 5 days of storage was significantly (p<0.05) higher in the control group than in other groups. The proportions of C18:1, MUFA, UFA and MUFA/SFA ratio were significantly (p<0.05) higher in the meat from Rhus verniciflua Stokes-supplemented Hanwoo than in the control group. Consequently, the meat from Rhus verniciflua Stokes-supplemented Hanwoo showed higher color stability, WHC, unsaturated fatty acids and retarded lipid oxidation compared to the control meat. In particular, dietary Rhus verniciflua Stokes supplementation with 4% extended storage life compared to the other groups.

• 한국의류학회지
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• 제38권3호
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• pp.372-385
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• 2014

Lignin is an abundant natural polymer in the biosphere and second only to cellulose; however, it is under-utilized and considered a waste. In this study, lignin was fabricated into nanofibers via electrospinning. The critical parameters that affected the electrospinnability and morphology of the resulting fibers were examined with the aim to utilize lignin as a resource for a new textile material. Poly(vinyl alcohol) (PVA) was added as a carrier polymer to facilitate the fiber formation of lignin, and the electrospun fibers were deposited on polyester (PET) nonwoven substrate. Eleven lignin/PVA hybrid solutions with a different lignin to PVA mass ratio were prepared and then electrospun to find an optimum concentration. Lignin nano-fibers were electrospun under a variety of conditions such as various feed rates, needle gauges, electric voltage, and tip-to-collector distances in order to find an optimum spinning condition. We found that the optimum concentration for electrospinning was a 5wt% PVA precursor solution upon the addition of lignin with the mass ratio of PVA:lignin=1:5.6. The viscosity of the lignin/PVA hybrid solution was determined as an important parameter that affected the electrospinning process; in addition, the interrelation between the viscosity of hybrid solution and the electrospinnability was examined. The solution viscosity increased with lignin loading, but exhibited a shear thinning behavior beyond a certain concentration that resulted in needle clogging. A steep increase in viscosity was also noted when the electrospun system started to form fibers. Consequently, the viscosity range to produce bead-free lignin nanofibers was revealed. The energy dispersive X-ray analysis confirmed that lignin remained after being transformed into nanofibers. The results indicate the possibility of developing a new fiber material that utilizes biomass with resulting fibers that can be applied to various applications such as filtration to wound dressing.

• 한국유기농업학회지
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• 제14권1호
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• pp.97-108
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• 2006

본 시험은 Spent bleaching clay(SBC) 첨가에 따라 반추위내의 발효특성과 이용율을 조사하기 위하여 Fistula가 장착된 홀스타인 3두를 공시하여 반추위내 발효성상을 조사하였다. 반추위내 pH 변화는 대조구와 SBC 2% 첨가구간에는 차이가 없었으나, SBC 4% 첨가에 의하여 낮아지는 경향이 인정되었다. 반추위내 $NH_3-N$의 함량은 SBC 4% 첨가구가 대조구와 SBC 2% 첨가구에 비하여 사료 급여 후 3시간째까지 높은 경향을 나타냈으나 이후 3처리구는 유사한 경향을 나타내었다. 한편 SBC의 첨가수준에 관계없이 반추위내 VFA의 함량은 변화가 없는 것으로 나타났다. 반추위내 건물 및 유기물 손실율은 SBC 4% 첨가구가 대조구 및 SBC 2% 첨가구에 비해서 배양초기에는 낮아지는 경향을 보였으나 이후 4처리간 차이는 인정되지 않았다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.791-793
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• 2015

최근 들어 UCC(User Created Contents) 및 VoD(Video on Demand) 등 멀티미디어 컨텐츠들이 늘어나고, IP-TV, Smart TV, OHTV(Open Hybrid TV) 등 다양한 서비스가 멀티 플랫폼(Multi-platform) 환경에서 제공되면서, 서비스에 대한 QoS 문제가 대두되고 있다. 이 문제를 해결하기 위해 네트워크를 효율적으로 활용하고, 콘텐츠 품질을 향상하기 위한 시스템이 필요하다. 이에 본 논문에서는 네트워크의 채널 상태와 동적 자원 사용량에 따라 멀티미디어 데이터의 전송을 TCP와 UDP를 적응적으로 사용하는 듀얼 스트리밍 시스템에 대해 설계 및 분석 한다. 또한 기존 TCP와 UDP 하나의 프로토콜을 사용한 스트리밍 시스템과의 차이점 및 효율성에 대해 분석한다. 이는 재난 및 의료분의의 응급시스템, 유비쿼터스 분야에 활용될 것으로 사료된다.

• 멤브레인
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• 제26권5호
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• pp.365-371
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• 2016

메탄을 순도 95% 이상으로 분리, 회수하기 위하여 메탄에 대한 분리특성이 우수한 폴리설폰 중공사 분리막 모듈을 2단으로 연결하고 재순환 흐름을 이용하여 회수율을 90% 이상으로 유지할 수 있도록 공정을 설계하였다. 이렇게 설계된 2단 공정을 통한 메탄 분리 거동 특성을 이론적으로 예측하기 위하여 Compaq Visual Fortran 6.6 소프트웨어를 이용하여 수치 해석하였다. 개발한 프로그램을 사용하여 수치 해석을 수행한 결과 공정 변수에 따라 최종 메탄의 농도 변화에 미치는 영향을 고찰할 수 있었다. 공급 기체 압력과 분리막 길이와 공급측 메탄 농도 증가, 유량이 감소함에 따라 최종 생산물 내 메탄 농도 증가를 관찰할 수 있었으며, 메탄의 회수율은 감소함을 알 수 있었다.

• 농업과학연구
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• 제46권2호
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• pp.285-292
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• 2019

This study was done to evaluate the effects of a mixture of essential oils and organic acid supplementation on growth performance, blood profiles, leg bone length and intestinal morphology in Ross broilers. A total of 40 Ross 308 broilers ($1140{\pm}80g$) were randomly allocated to 2 groups, a basal diet (CON) and a basal diet + 0.05% $Avi-protect^{(R)}$ (AVI, Mixture of 25% citric, 16.7 sorbic, 1.7% thymol, and 1.0% vanillin), with 20 replicates for every group and 1 chicken per replicate per cage. The broilers were raised in a temperature-controlled room maintained at $24{\pm}1^{\circ}C$ and $50{\pm}5%$ humidity. The body weight (p < 0.05) and weight gain (p < 0.05) of the broilers were increased in the AVI group compared with the CON group. The triglyceride (p < 0.05) and low density lipoprotein (LDL) (p < 0.05) contents were significantly decreased in the AVI group compared with the CON group. There was no significant difference in the leg bone length between the AVI and CON groups (p > 0.05). The villi height (p < 0.05) and goblet cell count (p < 0.05) were significantly increased in the AVI group compared with the CON group. In conclusion, $Avi-protect^{(R)}$ as a feed additive improved the growth performance and lipid metabolism and promoted the development of the intestinal morphology of broilers.

• 농업과학연구
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• 제47권4호
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• pp.1039-1048
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• 2020

Food waste causes various economic losses and environmental pollution problems such as soil pollution and groundwater pollution. Food waste has been used as a resource in various forms and has been used mostly for feed and composting. This study compared microalgal nutrient medium (BG-11) with food waste compost to determine the possibility of using it as a culture medium. Scenedesmus quadricauda was isolated and cultured in an eutrophic reservoir and incubated for 3 days in distilled water before laboratory use. Food waste compost was produced in two food waste processing facilities, and hot water was extracted in the laboratory to be used for microalgae cultivation. The growth curve of the microalgae was analyzed based on the Chl-a concentration measured during the experiment, and the growth rate of the microalgae grown in the food waste compost was compared with the growth rate of those grown in the nutrient medium. Food waste compost showed a similar growth rate to that of the nutrient medium, and there was a difference depending on the manufacturing facility. The growth of microalgae in such food waste was further amplified when trace elements were added and showed better growth than that of the nutrient media. Particularly, when trace elements were added, the growth rate increased, and the growth period was further extended. Therefore, food waste compost can be sufficiently utilized as a microalgal culture medium, and if trace elements are added, it is considered that microalgae can be more effectively cultured compared to the existing nutrient medium.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.185-196
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• 2022

The Internet of Things (IoT) has become more and more widespread in recent years, thus attackers are placing greater emphasis on IoT environments. The IoT connects a large number of smart devices via wired and wireless networks that incorporate sensors or actuators in order to produce and share meaningful information. Attackers employed IoT devices as bots to assault the target server; however, because of their resource limitations, these devices are easily infected with IoT malware. The Distributed Denial of Service (DDoS) is one of the many security problems that might arise in an IoT context. DDOS attempt involves flooding a target server with irrelevant requests in an effort to disrupt it fully or partially. This worst practice blocks the legitimate user requests from being processed. We explored an intelligent intrusion detection system (IIDS) using a particular sort of machine learning, such as Artificial Neural Networks, (ANN) in order to handle and mitigate this type of cyber-attacks. In this research paper Feed-Forward Neural Network (FNN) is tested for detecting the DDOS attacks using a modified version of the KDD Cup 99 dataset. The aim of this paper is to determine the performance of the most effective and efficient Back-propagation algorithms among several algorithms and check the potential capability of ANN- based network model as a classifier to counteract the cyber-attacks in IoT environments. We have found that except Gradient Descent with Momentum Algorithm, the success rate obtained by the other three optimized and effective Back- Propagation algorithms is above 99.00%. The experimental findings showed that the accuracy rate of the proposed method using ANN is satisfactory.