• Structural Engineering and Mechanics
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• v.11 no.2
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• pp.199-210
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• 2001

Axially compressed circular cylinders repeat symmetry-breaking bifurcation in the postbuckling region. There exist stable equilibria with all symmetry broken in the buckled configuration, and the minimum postbuckling strength is attained at the deep bottom of closely spaced equilibrium branches. The load level corresponding to such postbuckling stable solutions is usually much lower than the initial buckling load and may serve as a strength limit in shell stability design. The primary concern in the present paper is to compute these possible postbuckling stable solutions at the deep bottom of the postbuckling region. Two computational approaches are used for this purpose. One is the application of individual procedures in computational bifurcation theory. Path-tracing, pinpointing bifurcation points and (local) branch-switching are all applied to follow carefully the postbuckling branches with the decreasing load in order to attain the target at the bottom of the postbuckling region. The buckled shell configuration loses its symmetry stepwise after each (local) branch-switching procedure. The other is to introduce the idea of path jumping (namely, generalized global branch-switching) with static imperfection. The static response of the cylinder under two-parameter loading is computed to enable a direct access to postbuckling equilibria from the prebuckling state. In the numerical example of an elastic perfect circular cylinder, stable postbuckling solutions are computed in these two approaches. It is demonstrated that a direct path jump from the undeformed state to postbuckling stable equilibria is possible for an appropriate choice of static perturbations.

• Journal of environmental and Sanitary engineering
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• v.20 no.1 s.55
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• pp.12-22
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• 2005

This study was performed to survey distribution of microorganisms and food-borne pathogenic bacterium in order to estimate microbiological safety in seonsik and saengsik. Total aerobic bacteria was detected over $10^5\;CFU/g$ in raw materials($4.3\%$) and products($35.7\%$) of saengsik. Coliforms were detected over $10^2\;CFU/g$ in seonsik products($27.3\%$) and in raw materials($4.3\%$) and products($35.7\%$) of saengsik. Cl. perfringens was detected in saengsik products($4.8\%$). B. cereus was detected in raw materials($12.5\%$) and products($18.2\%$) of seonsik and raw materials($13.0\%$) and products($23.8\%$) of saengsik. Concentration and detection rate of microorganisms in products were higher than raw materials. These results show some food hygiene problems but do not cause food poisoning because concentration of Clostridium perfringens and B. cereus were lower than $10^5\;CFU/g$.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.664-671
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• 2012

This paper presents the application of Unified Power Flow Controller (UPFC) in order to simultaneous control of power flow and voltage and also damping of Low Frequency Oscillations (LFO) at a Single-Machine Infinite-Bus (SMIB) power system installed with UPFC. PI type controllers are commonly used controllers for UPFC control. But for the sake of some drawbacks of PI type controllers, the scope for finding a better control scheme still remains. In this regard, in this paper the new IP type controllers are considered as UPFC controllers. The parameters of these IP type controllers are tuned using Genetic Algorithms (GA). Also a stabilizer supplementary controller based UPFC is considered for increasing power system damping. To show the ability of IP controllers, this controller is compared with classical PI type controllers. Simulation results emphasis on the better performance of IP controller in comparison with PI controller.

• Ocean and Polar Research
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• v.22 no.2
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• pp.81-90
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• 2000

Supposed construction of a large port in the mouth of Tuman River requires careful examination of possible unfavorable ecological consequences for the Far Eastern Federal Marine Reserve. Since the Tuman River is the largest source of suspended material and possible contaminants flowing into the sea, and in order to understand how this material is allocated in the coastal zone, analyses are needed to check possible pathways of water transport and circulation system in the region. Linearized shallow water equations were used for numerical simulation of the wind-driven circulation to the north off the Tuman River mouth. The model results satisfactorily agreed with in situ data. The model circulation patterns are largely dependent on the wind direction and are conformed by the distribution of bottom sediments, and by the location of organic carbon and some pollutants accumulation zones. The most unfavorable situation for the Marine Reserve is the case of the southwesterly wind; even with quite moderate wind, the waters polluted by the run-off from the Tuman River can attain the south section of the Marine Reserve during the diurnal period.

• Journal of Multimedia Information System
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• v.3 no.3
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• pp.97-102
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• 2016

Deep learning enables machines to have perception and can potentially outperform humans in the medical field. It can save a lot of time and reduce human error by detecting certain patterns from medical images without being trained. The main goal of this paper is to build the optimal model for breast mass classification by applying various methods that influence the performance of Convolutional Neural Network (CNN). Google's newly developed software library Tensorflow was used to build CNN and the mammogram dataset used in this study was obtained from 340 breast cancer cases. The best classification performance we achieved was an accuracy of 0.887, sensitivity of 0.903, and specificity of 0.869 for normal tissue versus malignant mass classification with augmented data, more convolutional filters, and ADAM optimizer. A limitation of this method, however, was that it only considered malignant masses which are relatively easier to classify than benign masses. Therefore, further studies are required in order to properly classify any given data for medical uses.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2676-2685
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• 1998

In order to improve the branch prediction accuracy and to reduce the BTB miss rate, this paper proposes a two-level BTB structure that adds small-sized victim BTB to the convetional BTB. With small cost, two-level BTB can reduce the BTB miss rate as well as improve the prediction accuracy of the hybrid branch prediction strategy which combines dynamic prediction and static prediction. Through the trace-driven simulation of four bechmark programs, the performance improvement by the proposed two-level BTB structure is analysed and validated. Our proposed BTB structure can improve the BTB miss rate by 26.5% and the misprediction rate by 26.75%

• Korean Journal of Veterinary Service
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• v.40 no.4
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• pp.245-251
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• 2017

Cold air or ice water are used to chill poultry carcasses after slaughter. In order to compare the microbial reduction effect of two different chilling systems in poultry carcasses, Pre-and post-chilled carcass samples were tested for contamination agents such as aerobic bacteria counts, E. coli counts and Salmonella spp. counts. Water chilling system showed higher reduction ratio of bacteria than air chilling system during the three seasons. Also, aging of slaughter facility was related with bacterial contamination of pre-chilld carcasses. And additional volatile basic nitrogen (VBN) test were conducted in poultry packing meats and it increased steadily during 15 days. VBN at 8~9 days were over 13 mg% with putrid smell. Poultry packing meats by water chilling system were fresher than air chilling system during early storage time. But those decayed faster after 9 days.

• Journal of Power Electronics
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• v.13 no.5
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• pp.877-883
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• 2013

This paper discussed a transformer-less shunt static synchronous compensator (STATCOM) with consideration of the following aspects: fast compensation of the reactive power, harmonic cancelation and reducing the unbalancing of the 3-phase source side currents. The STATCOM control algorithm is based on the theory of instantaneous reactive power (P-Q theory). A self charging technique is proposed to regulate the dc capacitor voltage at a desired level with the use of a PI controller. In order to regulate the DC link voltage, an off-line Genetic Algorithm (GA) is used to tune the coefficients of the PI controller. This algorithm arranged these coefficients while considering the importance of three factors in the DC link voltage response: overshoot, settling time and rising time. For this investigation, the entire system including the STATCOM, network, harmonics and unbalancing load are simulated in MATLAB/SIMULINK. After that, a 35KVA STATCOM laboratory setup test including two parallel converter modules is designed and the control algorithm is executed on a TMS320F2812 controller platform.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.618-622
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• 2010

Cost-effective purification methods of silicon were carried out in order to replace the conventional Siemens method for solar grade silicon. Firstly, acid leaching which is a hydrometallurgical process was preceded with grinded silicon powders of metallurgical grade (~99% purity) to remove metallic impurities. Then, plasma treatments were performed with the leached silicon powders of 99.94% purity by argon plasma at 30 kW power under atmospheric pressure. Plasma treatment was specifically efficient for removing Zr, Y, and P but not for Al and B. Another purification step by EB treatment was also studied for the 99.92% silicon lump which resulted in the fast removal of boron and aluminum. That means the two methods are effective alternative tools for removing the doping elements like boron and phosphor.

• Journal of International Society for Simulation Surgery
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• v.3 no.2
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• pp.64-68
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• 2016

Aim Robots are able to increase safety for pharmacy staff as separating from toxicity of anti-cancer drugs. For patient safety, it would provide right dose of the drugs. Additionally, it can reduce price of the drugs. Therefore, in this study, a novel compounding anticancer drugs robot system (Dupalro) was developed. Methods We used the robot system, Motoman dual-arm robot from YASKAWA, Japan and medications which are adapted for the robot were constructed. In order to develop a process of compounding anticancer drugs, information about five medications that are required to make anticancer drugs in hospitals was used. Results System for the five types of medications was constructed, and relating procedures for anticancer drugs compounding robot were developed. Conclusion Dupalro successfully was able to not only provide incremental safety and efficiency for both patients and pharmacy staff, but also decrease price of anticancer drugs.