• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1055-1062
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• 2000

Objectives : Burst fracture of the lower lumbar spine(L3-L5) is rare and has some different features compare to that of thoracolumbar junction. Lower lumbar spine is flexible segments located deeply, and has physiologic lordosis. All of these contribute to making surgical approach difficult. Generally, lower lumbar burst fracture is managed either anteriorly or posteriorly with various fixation and fusion methods. But there is no general guideline or consensus regarding the proper approach for such lesion. We have tried to find out the influencing factors for selecting the surgical approach through the analysis of lower lumbar burst fractures treated for last 4 years(1994.3-1998.3). Method : This study includes 15 patients(male : 10, female : 5, age range 20-59 years with mean age of 36.7 years, L3 : 8 cases, L4 : 5 cases, L5 : 2 cases). Patients were classified into anterior(AO) and posterior operated(PO) groups. We investigated clinical findings, injured column, operation methods, and changes in follow-up radiologic study (kyphotic angle) to determine the considerable factors in selecting the surgical approaches. Results : There were 5 AO and 10 PO patients. Anterior operation were performed with AIF with Kaneda or Z-plate and posterior operation were done with pedicle screw fixation with PLIF with cages or posterolateral fusion. Canal compression was 46.6% in AO and 38.8% in PO. The degree of kyphotic angle correction were 10.7 degree(AO) and 8.5 degree(PO), respectively. There was no statistical difference between anterior and posterior operation group. All patients showed good surgical outcome without complications. Conclusion : Anterior operation provided good in kyphotic angle correction and firm anterior strut graft, but it difficulty arose in accessing the lesions below L4 vertebra. While posterior approach showed less correction of kyphotic angle, it required less time and provided better results for accompanied adjacent lesion and pathology such as epidural hematoma. The level of injury, canal compression, biomechanics, multiplicity, and pathology are considered to be important factors in selection of the surgical approach.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.4
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• pp.735-751
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• 2012

A study in which tourist attraction selection attributes of tourists are identified focused on experience of tourists in attraction site and relationship between impacts of tourist attraction selection attributes on satisfaction and behavioral intentions is examined is very necessary. Therefore, the purpose of this study is to investigate the impact of Daejeon ppuri park tourist attraction selection attribute on tourist satisfaction and behavioral intentions through survey targeting tourists after they visit Daejeon ppuri park. Relationship between impacts of tourist attraction selection attributes on satisfaction and behavioral intentions and mediated effect of image of tourist attraction in relationship between impacts of tourist attraction selection attributes on satisfaction and behavioral intentions are analyzed through empirical analysis. As the results of verification of the hypothesis in this study, 'activity and experience' and 'approach and cost' factors show higher impact on satisfaction in relationship between Daejeon ppuri park tourist attraction selection attribute and tourist satisfaction. In addition, it shows that 'activity and experience', 'approach and cost' and 'familiarity' factors have impact on behavioral intentions in relationship between tourist attraction selection attribute and behavioral intentions. Finally, it shows the significant mediated effect in relationship between tourist attraction selection attribute and tourist satisfaction depending on mediated effect of image of tourist attraction, but it does not work as mediated function in behavioral intentions.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.1
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• pp.101-108
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• 2010

In this paper, we proposed a new lazy classifier with fuzzy k-nearest neighbors approach and feature selection which is based on reconstruction error. Reconstruction error is the performance index for locally linear reconstruction. When a new query point is given, fuzzy k-nearest neighbors approach defines the local area where the local classifier is available and assigns the weighting values to the data patterns which are involved within the local area. After defining the local area and assigning the weighting value, the feature selection is carried out to reduce the dimension of the feature space. When some features are selected in terms of the reconstruction error, the local classifier which is a sort of polynomial is developed using weighted least square estimation. In addition, the experimental application covers a comparative analysis including several previously commonly encountered methods such as standard neural networks, support vector machine, linear discriminant analysis, and C4.5 trees.

• Industrial Engineering and Management Systems
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• v.9 no.2
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• pp.88-96
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• 2010

This paper presents a two-phase quantitative framework to aid the decision making process for effective selection of an efficient freight logistics hub from 8 alternatives in Thailand on the North-South economic corridor. Phase 1 employs both multiple regression and Pearson Feature selection to find the important criteria, as defined by logistics hub score, and to reduce number of criteria by eliminating the less important criteria. The result of Pearson Feature selection indicated that only 5 of 15 criteria affected the logistics hub score. Moreover, Genetic Algorithm (GA) was constructed from original 15 criteria data set to find the relationship between logistics criteria and freight logistics hub score. As a result, the statistical tools are provided the same 5 important criteria, affecting logistics hub score from GA, and data mining tool. Phase 2 performs the fuzzy stochastic AHP analysis with the five important criteria. This approach could help to gain insight into how the imprecision in judgment ratios may affect their alternatives toward the best solution and how the best alternative may be identified with certain confidence. The main objective of the paper is to find the best alternative for selecting freight logistics hub under proper criteria. The experimental results show that by using this approach, Chiang Mai province is the best place with the confidence interval 95%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1551-1556
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• 2012

This study proposes an efficient portfolio selection methodology for the listed corporations in KOSPI with consideration of managerial efficiency. For each industrial sector classified by KRX(Korea Exchange), the proposed method carries out an efficiency analysis using DEA (Data envelopment analysis) approach and for the efficient corporations filtered by DEA, construct portfolio using Markowitz's Model. In order to show the effectiveness of the proposed method, we constructed annually portfolios for 4 years (2007-2010) out of 600 listed corporations in KOSPI and KOSDAQ, and proved that our portfolios are superior to benchmark portfolios in terms of rate of returns.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.457-468
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• 2003

Active ingredients have been around in cosmetics for a long time but have they really resulted in active cosmetic products\ulcorner In order to achieve this, the right active needs to be delivered to the right location at the right concentration for the correct period of time. And the extent (and therefore the concentration) of this delivery depends on the formulation. From a rather theoretical approach based on the polarity of the active ingredient, the stratum corneum and the oil phase, the Relative Polarity Index was established that enables the selection of a suitable emollient for ensuring skin penetration of the active ingredient. Practical examples subsequently show the validity of this approach that demonstrates that one can regulate the delivery of an active molecule (and therefore the efficacy of a cosmetic formulation) by selection and control of the emollient system. Cosmetic formulations are generally quite complex mixtures and subsequent experiments using different emulsifier systems indicated that this component of a cosmetic formulation could also have an impact on steering the active ingredient to the right layer of the skin, although it is too early to be able to derive general rules from this.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.1911-1930
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• 2017

Overlay routing has emerged as a promising approach to improve reliability and efficiency of the Internet. The key to overlay routing is the placement and maintenance of the overlay infrastructure, especially, the selection and placement of key relay nodes. Spurred by the observation that a few relay nodes with high betweenness centrality can provide more optimal routes for a large number of node pairs, we propose a resilient routing overlay network construction method by introducing Super-Relay nodes. In detail, we present the K-Minimum Spanning Tree with Super-Relay nodes algorithm (SR-KMST), in which we focus on the selection and connection of Super-Relay nodes to optimize the routing quality in a resilient and scalable manner. For the simultaneous path failures between the default physical path and the overlay backup path, we also address the selection of recovery path. The objective is to select a proper one-hop recovery path with minimum cost in path probing and measurement. Simulations based on a real ISP network and a synthetic Internet topology show that our approach can provide high-quality overlay routing service, while achieving good robustness.

• Smart Media Journal
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• v.9 no.1
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• pp.23-29
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• 2020

This paper presents an approach for dynamic hand gesture recognition by using algorithm based on 3D Convolutional Neural Network (3D_CNN), which is later extended to 3D Residual Networks (3D_ResNet), and the neural network based key frame selection. Typically, 3D deep neural network is used to classify gestures from the input of image frames, randomly sampled from a video data. In this work, to improve the classification performance, we employ key frames which represent the overall video, as the input of the classification network. The key frames are extracted by SegNet instead of conventional clustering algorithms for video summarization (VSUMM) which require heavy computation. By using a deep neural network, key frame selection can be performed in a real-time system. Experiments are conducted using 3D convolutional kernels such as 3D_CNN, Inflated 3D_CNN (I3D) and 3D_ResNet for gesture classification. Our algorithm achieved up to 97.8% of classification accuracy on the Cambridge gesture dataset. The experimental results show that the proposed approach is efficient and outperforms existing methods.

• Korean Management Science Review
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• v.24 no.2
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• pp.143-155
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• 2007

The purpose of this paper is to develop a new method for information system sizing and selection based on a hybrid mixture of simulation and genetic algorithm, and to show its cost-effectiveness by applying it to a real world problem. To serve this purpose, we propose an operational model which identifies a set of system alternatives using simulation, and determines the optimal one using genetic algorithm. Specifically, with simulation, we generate probability distributions describing real data gathered from actual system, which can overcome the major weakness of the existing methodology that normally employs point estimates of the actual data and constant correction factors without theoretical rationale. We next search for the optimal combination of H/W, the number of CPUs, and S/W, which meets both of our business goals of incurring low TCO(total cost of ownership) and maintaining a good level of transaction processing performance. Experimental result shows the proposed method in this paper saves the cost while it preserves the system's capacity within allowable performance range.

• Journal of Distribution Science
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• v.15 no.6
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• pp.37-46
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• 2017

Purpose - The paper aims to propose an optimization model for supporting the buyer-seller negotiations. We consider the price, quality, and delivery as evaluation criteria, also recognized as objectives for negotiation. Research design, data, and methodology - The methodology used in this paper involves the input-oriented DEA with the inverse optimization. Under the existence of several potential suppliers, the price would be considered to be the decision variable to conclude the negotiation so as to meet the desired level of the quality and delivery. The data set for six suppliers with three criteria is examined by the proposed approach. Results - We present the decision aid model by displaying the price spectrum as the changes of desired output levels. It overcomes the shortcomings from previous researches mainly based on the discrete types of scenario generations. This approach shows that the obtained results help the buyer understand the trade-offs between price and performance when he/she considers the negotiation. Conclusions - The paper contributes to the numerical models for buyer-supplier negotiation in that the model for the supplier evaluation and selection is closely linked with the model for negotiation. In addition, it eliminates the unrealistic negotiation strategy, and provides the negotiation strategies that the buyer would not shift the burden on suppliers by maintaining the current efficiency.