• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.141.1-141.1
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• 2011

New CCD BVR light curves of BD And are presented. Our light curves with nearly equal depths for both primary and secondary eclipses show well-defined photometric waves outside eclipse for all of BVR bandpasses. The orbital period is greatly revised as $0.^d92580519$ which is twice longer than that known previously. Sixteen timings from our observations and thirteen ones from the SuperWASP measurements were calculated. All available timings over 76 years, including ours, were analyzed to figure out the dynamical behavior of the system. It was found that the recent CCD O-C residuals varied in a cyclical way with a period of $9.^y18$ and a semi-amplitude of $0.^d0046$. The secondary period of $9.^y18$ is the most shortest one among those which have been ever found in the short period RS CVn binary stars. The periodic variation most likely arises from the light-travel time effect due to a low-mass ($m_3{\sim}0.88\;M_{\odot}$) tertiary companion moving in an orbit with an large eccentricity ($e_3$=0.70) and a low inclination ($i_3{\sim}28^{\circ}$). The Applegate mechanism could not operate properly in both components because the model parameters require too much large luminosity changes of ${\Delta}L/L_{p,s}$ > 10. The new light curves were synthesized using the 2003 version of Wilson-Divinney code. It was found useful to model two huge spots on the surface of the hotter star and a third-light in order to minimize the residuals from the observations. Astronomical basic parameters were deduced from our photometric solution.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.305-312
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• 2010

The aim of this study is to find an analytic solution to the problem of determining the optimal capacity of a batch-storage network to meet demand for finished products in a system undergoing joint random variations of operating time and batch material loss. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to joint random variations in the cycle time and batch size. The production processes have also joint random variations in cycle time and product quantity. The spoiled materials are treated through regeneration or waste disposal processes. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced. The proposed method has the potential to rapidly provide very useful data on which to base investment decisions during the early plant design stage. It should be of particular use when these decisions must be made in a highly uncertain business environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.151-156
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• 2020

To analyze the diffraction properties of optical signals and the significant impacts of tapered sidewall profile at periodic trapezoidal 2D diffraction gratings, Toeplitz dielectric tensor is first defined and formulated by 2D spatial Fourier expansions associated with trapezoidal profile. The characteristic modes in each layer is then based on eigenvalue problem, and the complete solution is found rigorously in terms of modal transmission-line theory (MTLT) to address the pertinent boundary-value problems. Based on those one, the numerical analysis is performed on how the tapered side profile of grating structures with trapezoidal refractive index distribution affects the design of a sub-wavelength grating reflector. The numerical results reveal that this tapered sidewall profile plays a critical role in determining the reflection bandwidth, the average reflectance, and the band edge.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.3049-3054
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• 2014

PST stands for the Premium Sales Tool for Product Consulting is customized product catalog system. In other words, the product classification categories of content for consulting and sales to customers by providing useful information for the maximization of an overall system. These problems with mobility and flexibility of updating the solution to integrate mobile with mobile devices, but high-performance high-resolutions era content data continuously, but still it is difficult to handle. In this paper, to solve this problem, depending on the user's gesture by allowing periodic allocation and release of a problem for load generation enhanced by improving the PST system has been designed and implemented. Implementation was a result of the test the performance of the system, that PA system that has been provided by the traditional DA system show the allocation and the average 78% of the rate of decrease the load is released in the frequency of page, CPU utilization was reduced an average 72% I was confirmed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.117-126
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• 2015

This paper is to analyze an integrated production and inventory model in a single-vendor multi-buyer supply chain. The vendor is defined as the manufacturer and the buyers as the retailers. The product that the manufacturer produces is supplied to the retailers with constant periodic time interval. The production rate of the manufacturer is constant for the time. The demand of the retailers is constant for the time. The cycle time of the vendor is defined as the elapsed time from the start of the production to the start of the next production, while the cycle times of the buyer as the elapsed time between the adjacent supply times from the vendor to the buyer. The cycle times of the vendor and the buyers that minimizes the total cost in a supply chain are analyzed. The cost factors are the production setup cost and the inventory holding cost of the manufacturer, the ordering cost and the inventory holding cost of the retailers. The cycle time of the vendor is investigated through the cycle time that satisfies economic production quantity with the production setup cost and the inventory holding cost of the manufacturer. An integrated production and inventory model is formulated, and an algorithm is developed. An numerical example is presented to explain the algorithm. The solution of the algorithm for the numerical examples is compared with that of genetic algorithm. Numerical example shows that the vendor and the buyers can save cost by integrated decision making.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.1-8
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• 2003

The periodic safety review of operational nuclear power plants requires that the plants should keep a well organized environmental monitoring program. The past records of environment monitoring data were analyzed. and the tritium concentrations of the samples in the surface and ground water around Kori site were measured. It was shown that the tritium concentrations around the Kori site were slightly higher than that of natural background. The change of background tritium concentration was estimated through a numerical modeling. Two different versions of 7 compartments model - the world and the northern hemisphere - defined in NCRP-62 were modeled for the global tritium cycling. The numerical solution of the model was obtained using a computer program, AMBER. The four cases of tritium source-terms into the atmosphere were considered. The results showed that the tritium concentration in the surface soil water was higher than that in sea water or surface stream water. Also, it was shown that the tritium produced by the interaction between cosmic rays and the gases were the major source of tritium, and the tritium produced by nuclear weapon test decreased considerably.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.5
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• pp.1151-1160
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• 2016

A TrustZone-based rootkit detecting solution using a secure timer ensures the integrity of monitoring system, because ARM TrustZone technology provides isolated environments from a monitored OS against intercepting and modifying invoke commands. However, it is vulnerable to transient attack due to periodic monitoring. Also, Address Translation Redirection Attack (ATRA) cannot be detected, because the monitoring is operated by using the physical address of memory. To ameliorate this problem, we propose a snoop-based kernel introspection system. The proposed system can monitor a kernel memory in real-time by using a snooper, and detect memory-bound ATRA by introspecting kernel pages every context switch of processes. Experimental results show that the proposed system successfully protects the kernel memory without incurring any significant performance penalty in run-time.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.149-154
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• 2005

Conventionally used flocculation tanks require large space and high energy requirement for mixing. Static flocculators using gravel bed filter operate at a lower flow rate ($5-10m^3/m^2{\cdot}h$). Further, the cleaning of this system is difficult. A novel high rate static flocculator/filter developed at UTS packed with buoyant media such as polystyrene, polypropylene has been found to operate at higher filtration rates (30-45 $5-10m^3/m^2{\cdot}h$). They can easily be cleaned with minimal energy. Detailed experiments conducted with an artificial kaolin clay solution show that buoyant media is an excellent static flocculator in producing uniform filterable microflocs (12-15 m) even when it is operated at a high rate of 30-40 m/h. Detailed filtration experiments were conducted in a wastewater treatment plant to treat the biologically treated effluent with a floating media of depth of 120 cm. This filter was able to remove majority of phosphorus and remaining solids. It reduced significantly the fecal coliforms and fecal streptoccoci, thus requiring less amount of chlorine for disinfection. The advantage of this system is the low energy and water requirement for cleaning of filter bed. The periodic backwash adopted 30 seconds air and water and 30 seconds water cleaning every 90 minutes filter operation. Thisis equivalent to 1-2% of filtered water production. Mechanical cleaning system on the other hand, requires very low energy requirement (<1% of filtered water production).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.261-269
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• 2019

This study investigates a method of designing pixel-type frequency selective surfaces(FSS) with flexibility while considering factors, such as polarization and incident angle. Among the various methods used to solve the discrete space problem when designing a pixel-type FSS, the binary particle swarm optimization(BPSO) algorithm is one of the most applicable techniques to determine the periodic structure pattern of an FSS. Therefore, a method of efficiently designing FSS with roll-off band pass characteristics using an improved BPSO algorithm is proposed. To solve the convergence problem in the fitness function design to induce particles in the desired solution, FSS with desired roll-off wave characteristics can be easily obtained by applying a fitness function using "slope" as an input parameter.

• Molecules and Cells
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• v.42 no.6
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• pp.470-479
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• 2019

Interstitial cells of Cajal (ICCs) are pacemaker cells that exhibit periodic spontaneous depolarization in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of ghrelin and motilin on the pacemaker potentials of ICCs isolated from the mouse small intestine. Using the whole-cell patch-clamp configuration, we demonstrated that ghrelin depolarized pacemaker potentials of cultured ICCs in a dose-dependent manner. The ghrelin receptor antagonist [D-Lys] GHRP-6 completely inhibited this ghrelin-induced depolarization. Intracellular guanosine 5'-diphosphate-${\beta}$-S and pre-treatment with $Ca^{2+}$-free solution or thapsigargin also blocked the ghrelin-induced depolarization. To investigate the involvement of inositol triphosphate ($IP_3$), Rho kinase, and protein kinase C (PKC) in ghrelin-mediated pacemaker potential depolarization of ICCs, we used the $IP_3$ receptor inhibitors 2-aminoethoxydiphenyl borate and xestospongin C, the Rho kinase inhibitor Y-27632, and the PKC inhibitors staurosporine, Go6976, and rottlerin. All inhibitors except rottlerin blocked the ghrelin-induced pacemaker potential depolarization of ICCs. In addition, motilin depolarized the pacemaker potentials of ICCs in a similar dose-dependent manner as ghrelin, and this was also completely inhibited by [D-Lys] GHRP-6. These results suggest that ghrelin induced the pacemaker potential depolarization through the ghrelin receptor in a G protein-, $IP_3$-, Rho kinase-, and PKC-dependent manner via intracellular and extracellular $Ca^{2+}$ regulation. In addition, motilin was able to depolarize the pacemaker potentials of ICCs through the ghrelin receptor. Therefore, ghrelin and its receptor may modulate GI motility by acting on ICCs in the murine small intestine.