• Journal of Magnetics
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• v.21 no.4
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• pp.544-553
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• 2016

Torque ripple minimization without decrease in average torque is a vital attribute in the design of Synchronous Reluctance (SynRel) motor. As the design of SynRel motor is an arduous task, which encompasses many design variables, this work first analyses the significance of the effect of varying the geometrical parameters on average torque and torque ripple and then proposes an extensive optimization procedure to obtain configurations with improved average torque and minimized torque ripple. A hardware prototype is fabricated and tested. The Finite Element Analysis (FEA) software tool used for validating the test results is MagNet 7.6.0.8. Multi Objective Particle Swarm Optimization (MOPSO) is used to determine the various designs meeting the requirements of reduced torque ripple and improved torque performance. The results indicate the efficacy of the proposed methodology and substantiate the utilization of MOPSO as a significant tool for solving design problems related to SynRel motor.

• Bulletin of the Korean Mathematical Society
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• v.32 no.1
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• pp.45-56
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• 1995

D. H. Gottlieb [1, 2] studied the subgroups $G_n(X)$ of homotopy groups $\pi_n(X)$. In [5, 7, 10], the authors introduced subgroups $G_n(X, A)$ and $G_n^{Rel}(X, A) of \pi_n(X)$ and $\pi_n(X, A)$ respectively and showed that they fit together into a sequence $$ \cdots \to G_n(A) \longrightarrow^{i_*} G_n(X, A) \longrightarrow^{j_*} G_n^{Rel}(X, A) \longrightarrow^\partial $$ $$ \cdots \to G_1^{Rel}(X, A) \to G_0(A) \ to G_0(X, A) $$ where $i_*, j_*$ and \partial$ are restrictions of the usual homomorphisms of the homotopy sequence $$ \cdot \to^\partial \pi_n(A) \longrightarrow^{i_*} \pi_n(X) \longrightarrow^{j_*} \pi_n(X, A) \to \cdot \to \pi_0(A) \to \pi_0(X) $$.

• The KIPS Transactions:PartB
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• v.11B no.6
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• pp.709-716
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• 2004

According to the current increase of the usefulness of information by Internet Communication network, several methods are proposed in which a specific domain information nay be efficiently constructed and serviced. This paper proposes Relationship Grouping of Fuzzy Filtering Objects for Multimedia Statistic Post-office Box Construction. The proposed method exploits RelCRO( $D_{omain}$, Gi), RelSRO( $D_{omain}$, Gi) and FAS in order to group using (equation omitted)-cut. To know how well the proposed method is able to work, this paper have test against the methods with 1600 items of multimedia type information, and our system are compared with Random-Key, OGM and the proposed method. The results shows that the proposed method provides the better performance than the other methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.573-576
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• 2006

Recently, the standard work of the copyright of the Digital content is not completed. And the content providers are developing self's copyright protecting technique. here is some problem such as the confusion existed in the copyright protecting and management system. The reason is that the company using different technique when developing the Digital Contents. Now, there is a standard working leaded by the MPEG. It's called MPEG-21 Multimedia framework and the REL is parted of the Intellectual Property Management and Protection included the framework. And the REL's standard working is completed. The Intellectual Property Management and Protection system contain license server, tool server, metadate server and consume server. In this paper, In order to management and protect the Digital Content copyright, We applying the REL, One of the contents of the MPEG-21 framework to design and implementation the License Server manage the settlement and the consumption information and the Tool Server manage and transport the Tools used from Digital Contents formation to the Digital Contents consumption.

• Communications of the Korean Mathematical Society
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• v.19 no.1
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• pp.159-167
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• 2004

In [1], a relative root Nielsen number $N_{rel}(f;\;c)$ is introduced which is a homotopy invariant lower bound for the number of roots at $c\;{\in}\;Y$ for a map of pairs of spaces $f\;:\;(X,\;A)\;{\rightarrow}\;(Y,\;B)$. In this paper, we obtain a minimum theorem for $N_{rel}(f;\;c)$ under some new assumptions on the spaces and maps which are different from those in [1].

• Journal of the Korean Institute of Intelligent Systems
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• v.2 no.3
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• pp.17-21
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• 1992

In this paper we consider the notion of fuzzy relation as a generalization of that of fuzzy set. For a complete Heyting algebra L. the category set(L) of all L-fuzzy sets is shown to be a bireflective subcategory of the category Rel(L) of all L-fuzzy relations and L-fuzzy relation preserving maps. We investigate categorical structures of subcategories of Rel(L) in view of quasitopos. Among those categories, we include the category L-fuzzy similarity relations with respect to both max-min and max-product compositions, respectively, as a cartesian closed topological category. Moreover, we describe exponential objects explicitly in terms of function space.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.809-811
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• 2003

This brief review contains surveys of both four-component and two-component relativistic molecular theories. First the four-component relativistic approach is reviewed. Emphasis is placed on efficient computational schemes for the four-component Dirac-Hartree-Fock and Dirac-Kohn-Sham methods. Next, in the twocomponent relativistic framework, two relativistic Hamiltonians, RESC and higher-order Douglas-Kroll (DK), are introduced. An illustrative application is shown for the relativistic study on valence photoelectron spectrum of OsO₄. The developing four-component relativistic and approximate quasi-relativistic methods have been packed in a program suite named REL4D.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.164-164
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• 2003

We show that PCSC, a polysaccharide isolated from the sclerotium of Poria cocos with one percent sodium carbonate, significantly induces nitric oxide (NO) production and inducible NO synthase (iNOS) transcription through the activation of nuclear factor-$\kappa$B/Rel (NF-$\kappa$B/Rel).(omitted)

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.113-120
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• 2022

In this paper, we analyze the feasibility of the IP spoofing attack exploiting null security algorithms in 5G networks based on 3GPP standard specifications. According to 3GPP standard specifications, the initial Registration Request message is not protected by encryption and integrity. The IP spoofing attack exploits the vulnerability that allows a malicious gNB (next generation Node B) to modify the contents of the initial Registration Request message of a victim UE (User Equipment) before forwarding it to AMF (Access and Mobility Management Function). If the attack succeeds, the victim UE is disconnected from the 5G network and a malicious UE gets Internet services, while the 5G operator will charge the victim UE. In this paper, we analyze the feasibility of the IP spoofing attack by analyzing whether each signaling message composing the attack conforms to the 3GPP Rel-17 standard specifications. As a result of the analysis, it is determined that the IP spoofing attack is not feasible in the 5G system implemented according to the 3GPP Rel-17 standard specifications.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.47-53
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• 2014

LTE-Advanced is the evolved version of LTE which is currently in progress at the 3GPP. At present, as the number of smart phone users is rapidly increasing, the demand for ever more capacity is driven largely by video usage and high quality data communication and so on, this let more researchers study about LTE-A all over the world. LTE-A aims to achieve improved service and communication quality over 3G system at the aspect of throughput, peak data rate, latency, and spectral efficiency. Among various features in LTE-A, the multi-user MIMO(MU-MIMO), in which the base station transmits several streams to multiple receivers, has expected to give better quality for system. In this paper, we investigate performances of various types of downlink receivers with fixed number of antennas. we first review the development process from LTE to LTE-A. Second we introduce TM9 which is adopted in Rel.10 for MU-MIMO system, including the MU-MIMO system model and the explanation on the algorithm used in system. We also have brief introduction about sub-blocking in turbo decoding, finally we compare the performance between the uncoded case and coded case which is using turbo encoding.