• 한국항공운항학회지
• /
• 제16권2호
• /
• pp.21-27
• /
• 2008

An inverse method is introduced to construct the problem for the error analysis of the numerical solution of initial value problem. These problems constructed through this method have a known exact solution, even though analytical solutions are generally not obtainable. The process leading to the exact solution makes use of an initially available approximate numerical solution. A smooth interpolation of the approximate solution is forced to exactly satisfy the differential equation by analytically deriving a small forcing function to absorb all of the errors in the interpolated approximate solution. Using this special case exact solution, it is possible to investigate the relationship between global errors of a candidate numerical solution process and the associated tuning parameters for a given problem. Under the assumption that the original differential equation is well-posed with respect to the small perturbations, we thereby obtain valuable information about the optimal choice of the tuning parameters and the achievable accuracy of the numerical solution.

• Nuclear Engineering and Technology
• /
• 제36권2호
• /
• pp.165-174
• /
• 2004

The distributed resistance model has been recently implemented into the MATRA-LMR code in order to improve its prediction capability over the wire-wrap model for a flow blockage analysis in the LMR. The code capability has been investigated using experimental data observed in the FFM (Fuel Failure Mock-up)-2A and 5B for two typical flow conditions in a blocked channel. The predicted results by the MATRA-LMR with a distributed resistance model agreed well with the experimental data for wire-wrapped subchannels. However, it is suggested that the parameter n in the distributed resistance model needs to be calibrated accurately for a reasonable prediction of the temperature field under a low flow condition. Finally, the analyses of a blockage for the assembly of the KALIMER design are performed. Satisfactory results by the MATRA-LMR code were obtained through and rerified a comparison with results of the SABRE code.

• 한국정밀공학회지
• /
• 제13권5호
• /
• pp.38-43
• /
• 1996

Windowing routines have as their purpose the reduction of the sidelobes of a spectral output of the FFT or DFT routines. Windowing routines accomplish this by forcing the beginning and end of any sequence to approach each other in value. Since they must work with any sequence they force the beginning and ending samples near zero. To make up for this reduction in power, windowing routines give extra weight to the values near the middle of the sequence. The difference between windows is the way in which they transition from the low weights near the edges to the higher weights neqr the middle of the sequence. Signal-to-noise ratio(SNR) can be determined by the ratio of the output noisy signal variance to the input noisy signal variance of a window. Standard deviation of noise is reduced by windowing. Thus, the windowing operation improved the SNR of the noisy signal. This paper shows a performance estimation of windowing on a single tone with added Gaussian noise and uniform noise.

• 한방안이비인후피부과학회지
• /
• 제20권1호통권32호
• /
• pp.99-114
• /
• 2007

Objectives : Atopic dermatitis has a close relationship with damage of skin barrier function. To investigate the effects of Bangpungtongsungsan(BT) extract to the skin damage on mice model after atopic dermatitis elicitation, this study was done through forcing injury to mice's skin. Methods : The BALB/c mice were distributed into three groups: control(CON) group, atopic dermatitis(AD)-elicited group, Bangpungtongsungsan(BT)-treated group. AD-elicited and BT-treated group were caused AD according to the method of Christophers E., Mrowietz and Minehiro. The BT extract was administered for 48 hours to BT-treated group. We observed changes of external dermal formation, eosinophils in vasculature, lipid formation in stratum corneum, distribution of ceramide, distribution of capillary, $I{\kappa}B$ kinase(IKK) and induce nitric oxide synthase(iNOS) mRNA expression. We used the statistical methods of student t-test(p<0.05). Results : After dispensing BT extract into the AD-elicited group, the number of eosinophil as an atopic index in mice noticeably decreased and dermal injury decreased. Also the decrease of hyperplasia, degranulated mast cells, angiogenesis and substance P were shown. The lipid lamellae, lipid protect formation, were repaired and the distribution of ceramide which inhibit protein kinase C(PKC) activation increased, and the PKC caused inhibition of nuclear $factor(NF)-{\kappa}B$ activation. As a result of inhibition of $NF-{\kappa}B$ activation, iNOS production were inhibited and apoptotic cell were increased. Moreover the decrease of IKK and iNOS mRNA expression in BT-treated RAW 264.7 cell were noted. Conclusion : BT mitigated skin damage on mice model after atopic dermatitis elicitation through recovering skin barrier function and inhibiting nuclear $factor(NF)-{\kappa}B$ activation.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.546-551
• /
• 2004

In this paper, a level controller is designed with the neuro-fuzzy model based on Takagi-Sugeno fuzzy system. The fuzzy system is employed as the controller, which can be tuned by the neural network mechanism based on a gradient descent technique. The tuning mechanism will provide an optimal process input by forcing the process error to zero. The proposed controller provides the online tunable mode to adjust the consequent membership function parameters. The controller is implemented with M-file and graphic user interface (GUI) of Matlab program. The program uses MPIBM3 interface card to connect with the industrial processes In the experimentation, the proposed method is tested to vary of the process parameters, set points and load disturbance. Processes of one tank and two tanks are used to evaluate the efficiency of our controller. The results of the both processes are compared with two PID systems that are 3G25A-PIDO1-E and E5AK of OMRON. From the comparison results, our controller performance can be archived in the case of more robustness than the two PID systems.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권8호
• /
• pp.3621-3640
• /
• 2016

In the process of k-coverage of the target node, there will be a lot of data redundancy forcing the phenomenon of congestion which reduces network communication capability and coverage, and accelerates network energy consumption. Therefore, this paper proposes a novel energy balanced k-coverage control algorithm based on probability model (EBKCCA). The algorithm constructs the coverage network model by using the positional relationship between the nodes. By analyzing the network model, the coverage expected value of nodes and the minimum number of nodes in the monitoring area are given. In terms of energy consumption, this paper gives the proportion of energy conversion functions between working nodes and neighboring nodes. By using the function proportional to schedule low energy nodes, we achieve the energy balance of the whole network and optimizing network resources. The last simulation experiments indicate that this algorithm can not only improve the quality of network coverage, but also completely inhibit the rapid energy consumption of node, and extend the network lifetime.

• 한국잠사곤충학회지
• /
• 제13권2호
• /
• pp.135-139
• /
• 1971

1. Ecdysterone의 숙화 촉진작용은 5령 성식기이후에 유효하다. 2. Ecdysterone은 누에의 숙화를 촉진하고 또 초숙잠과 종숙잠간의 시차폭을 축소시킨다. 3. Ecdysterone의 숙화 촉진작용은 Ecdysterone의 식하량과 비례한다. 4. Dodecyl alcohol 주제의 DAT는 등족작용을 촉진한다. 5. Ecdysterone과 Dodecyl alcohol의 병용은 숙화와 등족을 촉진하여 자연상족을 가능케 하며 상족기술 개량에 공헌할 줄 믿는다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 추계학술대회 논문집
• /
• pp.109-114
• /
• 2001

Photovoltaic systems normally use a maximum power point tracking (MPPT) technique to continuously deliver the highest possible power to the load when variations in the insolation and temperature occur. A simple method of tracking the maximum power points (MPPs) and forcing the boost converter system to operate close to these points is presented through deriving small-signal model and transfer function of boost converter. This paper aims at modeling boost converter including equivalent series resistance of input reservoir capacitor by state-space-averaging method. In the future, properly designed controller for compensation will be constructed for maximum photovoltaic power tracking control.

• 대한원격탐사학회지
• /
• 제33권1호
• /
• pp.15-24
• /
• 2017

Jellyfish (cnidarian) are conspicuous in many marine ecosystems when in bloom. Despite their importance for the ecosystem structure and function, very few sampling programs are dedicated to sample jellyfish because they are patchily distributed and easily clogged plankton net. Although satellite remote sensing is an excellent observing tool for many phenomena in the ocean, their uses for monitoring jellyfish are not possible due to the coarse spatial resolutions. Hence, we developed the low altitude remote sensing platform to detect jellyfish in high resolutions, which allow us to monitor not only horizontal, but also vertical migration of them. Using low altitude remote sensing platform,we measured the jellyfish from the pier at the Chesapeake Biological Laboratory in Chesapeake Bay. The patterns observed included discrete patches, in rows that were aligned with waves that propagated from deeper regions, and aggregation around physical objects. The corresponding areas of exposed jellyfish on the sea surface were $0.1{\times}10^4pixel^2$, $0.3{\times}10^4pixel^2$, and $2.75{\times}10^4pixel^2$, respectively. Thus, the research result suggested that the migration of the jellyfish was related to the physical forcing in the sea surface.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.765-770
• /
• 2010

In this study, the behavior of underground pipeline subjected to pile driving is examined using the verified finite element model based on the field experiment. Young's modules of surface soil is varied and elastic modulus of the other soil layer is fixed. The pile driving force model proposed by Mounir E. Mabsout in 1999 was used and it was functions of time and of force. The forcing function applied on this study considers the kinetic energy of ram located at 1.2m height with 7 tonf. The 3-layered pipeline is composed of steel(inner) pipe, PUR(Polyurethane Resin, filler) and HDPE(outer) pipe, and the length/diameter of main steel pipe is 20m/0.8m(O.D). It is used for district heating pipes in Korea. The results are expressed in terms of Von Mises stress, displacement, and vibration velocity for each soil condition. From the results of the analyses, PUR which is originally intended as a thermal insulation of inner pipe shows performance as a structural member which distributes external pressure.