• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.54-56
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• 2015

In this paper, we investigate a physical-layer network coding (PNC) in a two-way relay channel (TWRC) where two sources send and receive data with each other by help of a relay node with multiple antennas. We focus on the multiple-access phase of the TWRC in this paper. It is assumed that the source nodes do not know the wireless channel and the wireless channel independently varies in time, that is, fast fading environments. At the relay node, the channel is assumed to be perfectly known. The relay node utilizes the channel sate information and applies maximum likelihood ratio for detecting received signals. Through extensive simulations, it is shown that a bit error rate (BER) performance becomes improved as the number of antennas at the relay node increases.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.11-18
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• 1997

By utilizing the technique to monitor the DC cell node voltages through circuit simulation, degradation of the static read operating margin In high load-resistor SRAM cell was examined, which is caused by parasitic resistances and transistor asymmetries in this cell structure. By selectively adding the parasitic resistances to an ideal cell, the influence of each parasitic resistance on the operating margin was examined, and then the cases with parasitic resistances in pairs were also examined. By selectively changing the channel width of cell transistors to generate cell asymmetry, the influence of cell asymmetry on the operating margin was also examined. Analyses on the operating margins were performed by comparing the supply voltage values at which two cell node voltages merge to a single value and the differences of cell node voltages at VDD=5V in the simulated node voltage characteristics. By determining the parasitic resistances and the transistor asymmetries which give the most serious effect on the static read-operation of SRAM cell from this analysis based on circuit simulated, a criteria was provided, which can be referred in the design of new SRAM cell structures.

• Korean Journal of Head & Neck Oncology
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• v.24 no.2
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• pp.189-193
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• 2008

Objectives：The incidence of micropapillary thyroid carcinoma(MPC) which is very good prognosis is increasing due to ultrasonography and accurate fine neede aspiration cytology. MPC defined papillary thyroid carcinoma below 1cm. According to the size, histophaothogic feature is different, lymph node metastasis and capsular invasion occur occasionally. So, we consider different treatment according to the size of MPC. Matrials and Methods：We reviewed and analyzed the record of 216 MPC patients operated at department of general surgery Busan Paik Hospital since 1995 January to 2005 Desember retrospectively. Result：The sex ratio was 1：9.29(male；21, female；195). Total thyroidectomy 20cases(9.3%), subtotal thyroidectomy 141cases(65%), lobectomy 52cases(24%), completion operation 3cases(1.4%) were done. Combined diseases were follicular carcinoma 4cases, follicular adenoma 11cases, thyroiditis 46cases, nodular hyperplasia 44cases. Lymph node metastasis 56cases and capsular invasion 56cases were presented. Group A(<5mm) was 53cases, group B(5-10mm) was 163cases. Group B showed higher lymph node metastasis and capsular invasion(P<0.05). Multiple carcinoma Showed higher capsular invasion than single carcinoma (P<0.05). Complications were post operative bleeding 1case, husky voice 1case, hypocalcemia 1case. Conclusion：We can consider more extensive operation in 5-10mm of MPC patients.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.2
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• pp.153-160
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• 2008

In this study, we propose a new three-node hybrid-mixed curved beam element with the relaxed-equiribrium stress functions for static analysis. The proposed element considering shear deformation is based on the Hellinger-Reissner variational principle. The stress functions are carefully chosen from three important considerations: (i) all the kinematic deformation modes must be suppressed, and (ii) the spurious constraints must be removed in the limiting behaviors via the field-consistency, and (iii) the relaxed equilibrium conditions could be incorporated because it might be impossible to select the stress functions and parameters to fully satisfy both the equiribrium conditions and the suppression of kinematic deformation modes in the three-node curved beam hybrid-mixed formulation. Numerical examples confirm the superior and stable behavior of the proposed element regardless of slenderness ratio and curvature. Besides, the proposed element shows the outstanding performance in predicting the stress resultant distributions.

• Fashion & Textile Research Journal
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• v.13 no.3
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• pp.418-424
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• 2011

The purpose of this study was to reveal the effects of the seam type on the fabric drape to provide the basic knowledge for proper seam type according to the design of sewing products. Seven kinds of specimens were constructed with seam (no seam, welt seam with over-edged finish, welt seam with bias bound finish, plain seam with over-edged finish, plain seam with bias bound finish, french seam, and flat fell seam) in wrap direction of the fabric. Using a drape measurement system involving two 18 cm diameter supporting disks, and a digital camera, the images of draped specimens were captured and processed. Drape behavior was evaluated in terms of drape coefficient, node number, and drape profile. Significant differences were found in drape coefficient by the seam types. The specimens with french seam and flat fell seam showed higher drape coefficients compared to those with welt seam and plain seam. Node numbers in the drape profiles showed positive correlation with the weight of the specimens, however, no significant differences were observed in node numbers by the seam types. Significant differences were found in the length of the seamed part by the seam types. The specimens with french seam and flat fell seam showed longer length of the seamed part compared to those with welt seam and plain seam. The ratio of the maximum length in the seam direction to the maximum length perpendicular to the seam direction showed significant differences by the seam types.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6B
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• pp.387-395
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• 2005

In this paper, we propose an end-to-end mobility management and TCP flow control scheme which considers different link characteristics for vertical handover environments. The end-to-end mobility management is performed by using SIP protocol. When a mobile node moves to a new network, it informs its movement of the correspondent node by sending SIP INFO message containing a new IP address which will be used in the new network. And then the corresponding node encapsulates all packets with the new IP address and sends them to the mobile node. in general, RTT of WLAN is shorter than RTT of cdma2000. when the MN moves from WLAN network to cdma2000 network, TCP retransmission timeout will be occurred in spite of non congestion situations. Thus, TCP congestion window size will be decreased and TCP throughput will be also decreased. To prevent this phenomenon, we propose a method using probe packets after handover to estimate a link delay of the new network. We also propose a method using bandwidth ratio of each network to update RTT. It is shown through NS-2 simulations that the proposed schemes can have better performance than the previous works.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.485-490
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• 2000

This paper describes the application of discretized continuum-type optimality criteria (DCOC) for minimum-cost design of the reinforced concrete frame structures consisting of beams and columns. The cost of construction as objective function which includes the costs of concrete, reinforced steel and formwork is minimized. The design constraints include limits on the maximum deflection at a prescribed node, bending and shear strengths in beams, uniaxial bending strength of columns according to design codes(CEB/FIP, 1990). In the first stage, only beams with uniform cross-sectional parameters per span are considered. But the steel ratio is allowed to vary freely. The cross-sectional parameters and steel ratio in each column are assumed to be uniform for practical reasons. Optimality criteria is given based on the well known Kuhn-Tucker necessary conditions, followed by an iterative procedure for designs when the design variables are the depth and the steel ratio. The versatility of the DCOC technique has been demonstrated by considering numerical examples which have one-bay four-storey frame.

• Journal of Information Technology Applications and Management
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• v.26 no.3
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• pp.19-27
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• 2019

In this study, we propose a methodology for predicting the movie audience based on movie information that can be easily acquired before opening and effectively distinguishing qualitative variables. In addition, we constructed a model to estimate the number of movie audiences at the time of data acquisition through the configured variables. Another purpose of this study is to provide a criterion for categorizing success of movies with qualitative characteristics. As an evaluation criterion, we used information gain ratio which is the node selection criterion of C4.5 algorithm. Through the procedure we have selected 416 movie data features. As a result of the multiple linear regression model, the performance of the regression model using the variables selection method based on the information gain ratio was excellent.

• Steel and Composite Structures
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• v.12 no.4
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• pp.275-289
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• 2012

In this paper the influence of stiffener location, rise/span ratio and fibre orientation on vibration behavior of corner supported hypar shells is studied by using a four-node hybrid stress finite element. The formulation of the element is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. Benchmark problems are solved to validate the approach and free vibration response of stiffened orthotropic hypar shells is studied both with respect to fundamental frequency and mode shapes by varying the location of stiffeners, rise/span ratio and fiber orientation.

• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.11-17
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• 1999

A three dimensional finite element generation code has been developed attaching simple blocks. Block can be either a quadrature or a cube depending on the dimension of a subject considered. Finite element serendipity basis functions are employed to map elements between the computational domain and the physical domain. Elements can be generated with wser defined progressive ratio for each block. For blocks to be connected properly, a block should have a consistent numbering scheme for vertices, side nodes, edges and surfaces. In addition the edge information such as the number of elements and the progressive ratio for each direction should also be checked for interfaces to have unique node numbers. Having done so, user can add blocks with little worry about the orientation of blocks, Since the present the present code has been written by a Visual Basic language, it can be developed easily for a user interactive manner under a Windows environment.