• Progress in Medical Physics
• /
• v.13 no.4
• /
• pp.181-186
• /
• 2002

The IMRT planning depends on the algorithm of each planning system and MLC performance of each Linac system. Yonsei Cancer Center introduced an IMRT System at the beginning of February, 2002. The system consists of CORVUS (Nomos, U.S.A.) treatment planning system, LANTIS, PRIMEVIEW and PRIMART (Siemens, U.S.A) linac system. The optimization of CORVUS planning system with PRIMART is an important task to make a desirable quality treatment plan. Our Step ＆ Shoot IMRT system uses Finite Size Pencil Beams (FSPB) dose model, simulated annealing optimization algorithm and IMFAST segmentation algorithm. We constructed treatment plans for four different patient cases with two basic beamlet sizes, 1.0$\times$1.0 $\textrm{cm}^2$ and 0.5$\times$1.0 $\textrm{cm}^2$, and four intensity steps, 5%, 10%, 20%, 33%. Each case's plan was evaluated with the dose volume histograms of target volumes and delivery efficiencies. The patient case of small target volume is sensitive at the change of intensity map's segmentation and it highlighted an effective treatment plan at marrow intensity step and small basic projection beamlet.

• The Journal of the Acoustical Society of Korea
• /
• v.24 no.4
• /
• pp.230-237
• /
• 2005

The angle-tracking of maneuvering targets is required to the state estimation and classification of targets in underwater acoustic systems. The Problem of angle-tracking multiple closed and crossing targets has been studied by various authors. Sword et al. Proposed a multiple target an91e-tracking algorithm using angular innovations of the targets during a sampling Period are estimated in the least square sense using the most recent estimate of the sensor output covariance matrix. This algorithm has attractive features of simple structure and avoidance of data association problem. Ryu et al. recently Proposed an effective multiple target angle-tracking algorithm which can obtain the angular innovations of the targets from a signal subspace instead of the sensor output covariance matrix. Hwang et al. improved the computational performance of a multiple target angle-tracking algorithm based on the fact that the steering vector and the noise subspace are orthogonal. These algorithms. however. are ineffective when a subset of the incident sources are coherent. In this Paper, we proposed a new multiple target angle-tracking algorithm for coherent and incoherent sources. The proposed algorithm uses the relationship between source steering vectors and the signal eigenvectors which are multiplied noise covariance matrix. The computer simulation results demonstrate the improved Performance of the Proposed algorithm.

• Geophysics and Geophysical Exploration
• /
• v.12 no.1
• /
• pp.77-84
• /
• 2009

Ground penetrating radar (GPR) is an effective tool for detecting shallow subsurface targets. In many GPR applications, these targets are veiled by the strong waves reflected from the ground surface, so that we need to apply a signal processing technique to separate the target signal from such strong signals. A pulse-compression technique is used in this research to compress the signal width so that it can be separated out from the strong contaminated clutter signals. This work introduces a filter algorithm to carry out pulse compression for GPR data, using a Wiener filtering technique. The filter is applied to synthetic and field GPR data acquired over a buried pipe. The discrimination method uses both the reflected signal from the target and the strong ground surface reflection as a reference signal for pulse compression. For a pulse-compression filter, reference signal selection is an important issue, because as the signal width is compressed the noise level will blow up, especially if the signal-to-noise ratio of the reference signal is low. Analysis of the results obtained from simulated and field GPR data indicates a significant improvement in the GPR image, good discrimination between the target reflection and the ground surface reflection, and better performance with reliable separation between them. However, at the same time the noise level slightly increases in field data, due to the wide bandwidth of the reference signal, which includes the higher-frequency components of noise. Using the ground-surface reflection as a reference signal we found that the pulse width could be compressed and the subsurface target reflection could be enhanced.

• The Journal of the Acoustical Society of Korea
• /
• v.21 no.5
• /
• pp.430-437
• /
• 2002

Having a variety of good characteristics against other pattern recognition techniques, the multilayer perceptron (MLP) has been widely used in speech recognition and speaker recognition. But, it is known that the error backpropagation (EBP) algorithm that MLP uses in learning has the defect that requires restricts long learning time, and it restricts severely the applications like speaker recognition and speaker adaptation requiring real time processing. Because the learning data for pattern recognition contain high redundancy, in order to increase the learning speed it is very effective to use the online-based learning methods, which update the weight vector of the MLP by the pattern. A typical online EBP algorithm applies the fixed learning rate for each update of the weight vector. Though a large amount of speedup with the online EBP can be obtained by choosing the appropriate fixed rate, firing the rate leads to the problem that the algorithm cannot respond effectively to different learning phases as the phases change and the number of patterns contributing to learning decreases. To solve this problem, this paper proposes a Changing rate and Omitting patterns in Instant Learning (COIL) method to apply the variable rate and the only patterns necessary to the learning phase when the phases come to change. In this paper, experimentations are conducted for speaker verification and speech recognition, and results are presented to verify the performance of the COIL.

• Nuclear Engineering and Technology
• /
• v.14 no.4
• /
• pp.186-195
• /
• 1982

The steam line break accident for Kori Unit 1 is analyzed by a code SYSRAN which calculates nuclear power and heat flux using the point kinetics equation and the lumped-parameter model and calculates system transient using the mass and energy balance equation with the assumption of uniform reactor coolant system pressure. The 1.4 f $t^2$ steam line break accident is analyzed at EOL (End of Life), hot shutdown condition in which case the accident would be most severe. The steam discharge rate is assumed to follow the Moody critical flow model. The results reveal the peak heat flux of 38% of nominal full power value at 60 second after the accident initiates, which is higher than the FSAR result of 26%. Trends for the transient are in good agreement with FSAR results. A sensitivity study shows that this accident is most sensitive to the moderator density coefficient and the lower plenum mixing factor. The DNBR calculation under the assumption of $F_{{\Delta}H}$=3.66, which is used in the FSAR with all the control and the shutdown assemblies inserted except one B bank assembly and of Fz=1.55 shows that minimum DNBR reaches 1.62 at 60 second, indicating that the fuel failure is not anticipated to occur. The point kinetics equation, the lumped-parameter model and the system transient model which uses the mass and energy balance equation are verified to be effective to follow the system transient phenomena of the nuclear power plants.lear power plants.

• Journal of the Korean Magnetics Society
• /
• v.25 no.3
• /
• pp.92-100
• /
• 2015

Electric Vehicle (EV) can be categorized by the driving method into in-wheel and in-line types. In-wheel type EV does not have transmission shaft, differential gear and other parts that are used in conventional cars, which simplifies and lightens the structure resulting in higher efficiency. In this paper, design method for in-wheel motor for automobiles using Parameter Map is proposed, and motor with continuous power of 5 kW is designed, built and its performance is verified. To decide the capacity of the in-wheel motor that meets the automobile's requirement, Vehicle Dynamic Simulation considering the total mass of vehicle, gear efficiency, effective radius of tire, slope ratio and others is performed. Through this step, the motor's capacity is decided and initial design to determine the motor shape and size is performed. Next, the motor parameters that meet the requirement is determined using parametric design that uses parametric map. After the motor parameters are decided using parametric map, optimal design to improve THD of back EMF, cogging torque, torque ripple and other factors is performed. The final design was built, and performance analysis and verification of the proposed method is conducted by performing load test.

• Journal of the Korean association of regional geographers
• /
• v.16 no.1
• /
• pp.34-47
• /
• 2010

The purpose of this study is to investigate the actual condition of commercial use of housing site in residential development complexes, and to derive effective future development plan by analyzing the influence of penetrating factors of commercial use. The foJlowing are the results of the analysis. First, characteristics of roads showed that the wider the widths of roads adjoining individual lots have more influences on commercial use penetration. This means that non-residential facilities tend to be located on regions where frequencies of uses are high, preferring regions having good transportation accessibility. Second, characteristics of adjacent usage showed that the distances of common housing, neighborhood facilities, schools to single-detached residential units acted as a factor for higher penetration ratio of commercial use when they were closer.ors an opposite, it showed as distances to parks were further, the penetration ratio were higher. This can be inferred that the condition of detached houses located closer to parks have pleasure environment, and act as a factor preventing commercial use penetration. Third, the official land price presents as a form of quality, as the analysis showed that the higher official land price, the more it acts as a factor increasing the penetration ratio of commercial use.

• Journal of Korea Technology Innovation Society
• /
• v.11 no.3
• /
• pp.376-399
• /
• 2008

Science and technology (S&T) is one of the most important elements in a nation's competitiveness. In an effort to strengthen their national competitiveness, all countries are focusing on upgrading the level of eir S&T. With these factors in mind, Korea has increased its support of national research and development (R&D). In recent years, this added support has resulted in an increased interest in the effectiveness of R&D. We have made continuous efforts to enhance the accountability and effectiveness of R&D by strengthening performance evaluation and considering R&D evaluation results during the budget review (appropriation) process. In order to change to a performance based system, we need to develop objective and scientific indicators to measure and evaluate the quality of the research performance of R&D programs. One of the primary research outcomes is publications. The impact factor of publications is widely used to evaluate overall journal quality and the quality of the papers published therein. However, the use of impact factors has been criticised because they can vary greatly when works from different subject areas are compared. In order to overcome this limitation, we have developed three kinds of qualitative indicators, which are functions of the impact factor. Two of these qualitative indicators, Modified Rank Normalized Impact Factor and Ordinal Rank Normalized Impact Factor, are based on order statistics (rank) for all journals from a specific specialty. The third qualitative indicator, Relative Field Impact Factor, uses the average impact factor of all journals within a subject category. We also suggest a quantitative indicator, Percentage of Contribution. In this study, we suggest 4 indicators and use them to evaluate the performance of outcomes from three R&D programs supported by the Ministry of Education, Science & Technology. We also perform a simulation study to verify the effectiveness of the proposed indicators. It can be shown that the proposed Ordinal Rank Normalized Impact Factor is the most reliable and effective indicator for comparing research performance across subject categories. However, we recommend using previous indicators in combination with the proposed indicators in this study for the research evaluation of R&D programs.

• Journal of Acupuncture Research
• /
• v.23 no.2
• /
• pp.73-90
• /
• 2006

Objectives : The effects of water extract of deer antler herbal-acupunture solution(DHS), prepared from the pilose antler of Cervus korea TEMMINCK var. mantchuricus Swinhoe (Nokyong), a traditional immunosuppressive and immune-activating Korean herbal- acupuncture, on collagen-induced arthritis(CIA:RA model) in mice was studied. Destruction of cartilage and bone are hallmarks of human rheumatoid arthritis, and controlling these erosive processes is the most challenging objective in the treatment of RA. Methods : We investigated the tissue protective effects of deer antler treatment using established murine collagen-induced arthritis(CIA) as a model. Potential synergy of low dosages of anti-inflammatory glucocorticosteroids and deer antler was also evaluated. Results : Treatment of established murine CIA with deer antler herbal-acupunture solution(DHS) $(10-50{\mu}g/day)$ suppressed disease activity and protected against cartilage and bone destruction. Although $10-50{\mu}g/day$ DHS had only a moderate effect on the inflammatory component of the disease activity, it strongly reduced cartilage pathology, as determined by histological examination. Serum cartilage oligomeric matrix protein(COMP) levels were significantly reduced, confirming decreased cartilage involvement. Histological analysis showed that bone destruction was prevented. DHS administration increased serum IL-1Ra levels and reduced anticollagen type II antibody levels. Treatment with low-dose $DHS(1{\mu}g/day)$ was ineffective in suppressing disease score, serum COMP or joint destruction. Synergistic suppression of both arthritis oseverity and COMP levels was noted when low-dose DHS was combined with prednisolone(0.05mg/kg/day), however, which in itself was not effective. Conclusion : DHS was shown to have the inhibiting effects against $IL-1{\alpha}-$ and $IL-1{\beta}-stimulated$ bone resorption. These results indicated that the DAS is not only highly stable and applicable to clinical uses in bone resorption, but also it will be served as a potent anti-inflammatory and anti-arthritic agents for treatment of human RA.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.3
• /
• pp.573-586
• /
• 2016

With the adoption of cloud computing, the number of companies that take advantage of cloud computing has increased. Additionally, various of existing service providers have moved their service onto the cloud and provided user with various cloud-based service. The management of user authentication and authorization in cloud-based service technology has become an important issue. This paper introduce a new technique for providing authentication and authorization with other inter-cloud IAM (Identity and Access Management). It is an essential and easy method for data sharing and communication between other cloud users. The proposed system uses the credentials of a user that has already joined an organization who would like to use other cloud services. When users of a cloud provider try to obtain access to the data of another cloud provider, part of credentials from IAM server will be forwarded to the cloud provider. Before the transaction, Access Agreement must be set for granting access to the resource of other Organization. a user can access the resource of other organization based on the control access configuration of the system. Using the above method, we could provide an effective and secure authentication system on the cloud.