• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.638-643
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• 2013

Chaos communication system has a sensitive characteristic to initial conditions, because completely another signal is generated when initial condition of chaos equation is changed subtly. Also, chaos communication systems have the characteristics of non-periodic, non-predictability, the broadband signal, such as ease of implementation. Due to these characteristics, security of chaos communication system generally is evaluated better than other systems. However, BER(Bit Error Rate) performance is evaluated worse than other digital system, because existing chaos communication system's transmitter and receiver are strong influence by interference signal and noise. So, research to improve the BER performance of the chaotic communication system is performed continuously. In this paper, We will propose a new CDSK(Correlation Delay Shift Keying) receiver for BER performance improvement. After we compare to the performance of existing CDSK receiver and proposed CDSK receiver, BER performance of proposed CDSK receiver evaluate. Also, when using the new CDSK receiver, we evaluate the BER performance according to the spreading factors and find an optimum spreading factor. If chaos communication system use a new CDSK receiver, BER performance is improved than existing CDSK receiver. Also, if spreading factor's value is increased, BER performance is improved, because it is not nearly affected by interference signal and noise.

• Knowledge Management Research
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• v.19 no.4
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• pp.39-58
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• 2018

This study explores the effects of business consulting on the business performance of firms by using a unique survey for various industry sectors in Korea. We attempt to build a consulting model that shows the structural relationship between consulting factors and consulting performance. Moreover, through the consulting model, we conduct the analysis of elasticity of consulting factors and the group analysis based on firm age. First, the findings show that all consulting factor has a positive impact on the consulting performance, but in the results of factor elasticity, they have a somewhat different impact. Second, while the support of CEOs is relatively more elastic than other consulting factors with respect to the completion of consulting projects, the institutional condition for consulting is relatively more elastic than other factors with respect to the contribution to business performance. Third, since the high-firm age group has a greater capacity to absorb and utilize external knowledge and resource, the consultant competency and institutional conditions have a more impact on the consulting performance than the low-firm age group. On the other hand, in the low-firm age group, the result indicates that the support of CEOs has a more impact in the consulting performance than the high-firm age group. According to the total effect, the support of CEOs in the entire model has the highest impact on the consulting performance. Thus, it is probably difficult to achieve the improvement of business performance through consulting as well as the successful consulting projects without the CEOs' commitment and awareness about the consulting projects.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1599-1607
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• 2009

In order to deal with severe competition in the construction market of developing countries, large contractors must continually improve their own performance and operation. Performance measurement is the heart of ceaseless improvement in organizations. Key performance indicators (KPIs) play a key role in measuring project management performance (PMP) of large contractors in developing countries. The main objective of this paper is to identify KPIs, which can be used to measure PMP of contractors, and then analyze the underlying relationships of these KPIs in order to gain insight into PMP of large construction firms in Vietnam construction industry (VCI). Literature reviews and the pilot survey provided 30 KPIs. Fourteen KPIs, which have the mean values higher than 3.0, were considered as important KPIs through a questionnaire survey of 32 professionals. Factor analysis of these KPIs was employed to categorize them. The results of the survey revealed that top six KPIs are construction time and cost, owner satisfaction on services and products, and quality management and project team performance. Factor analysis uncovered that 14 top-ranked KPIs can be grouped under six categories, namely: (1) construction input management, (2) owner satisfaction, (3) cost and quality, (4) manpower management, (5) subcontractor performance and (6) equipment management. The findings of this research can be used as a guideline to measure PMP of contractors in Vietnam as well as in other developing countries. Since contractors from a country to the other country may have the same manner to manage construction projects, the results of this study may be useful not only to practitioners and researchers in Vietnam but also to participants in other developing countries.

• Steel and Composite Structures
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• v.35 no.4
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• pp.599-609
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• 2020

The tension-only braced frames (TOBFs) are widely used as a lateral force resisting system (LFRS) in low-rise steel buildings due to their simplicity and economic advantage. However, the system has poor seismic energy dissipation capacity and pinched hysteresis behavior caused by early buckling of slender bracing members. The main concern in utilizing the TOBF system is the determination of appropriate performance factors for seismic design. A formalized approach to quantify the seismic performance factor (SPF) based on determining an acceptable margin of safety against collapse is introduced by FEMA P695. The methodology is applied in this paper to assess the SPFs of the TOBF systems. For this purpose, a trial value of the R factor was first employed to design and model a set of TOBF archetype structures. Afterwards, the level of safety against collapse provided by the assumed R factor was investigated by using the non-linear analysis procedure of FEMA P695 comprising incremental dynamic analysis (IDA) under a set of prescribed ground motions. It was found that the R factor of 3.0 is appropriate for safe design of TOBFs. Also, the system overstrength factor (Ω₀) was estimated as 2.0 by performing non-linear static analyses.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.115-122
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• 2017

In this paper, we propose a novel power factor compensation system using slidac. The proposed power factor compensation system compensates the power factor by adjusting the output voltage of the slidac. In the conventional power factor compensation system using capacitor bank method, the power factor compensation error occurs depending on the load condition due to the limitation of the compensation capacitor capacity. However, the proposed system can finely change slidac output voltage applied to the capacitor, therefore power factor can be compensated up to 100% without error. We compare the proposed system with the conventional system, and confirm that the proposed system has excellent power factor compensation performance through simulations and experiments. If the proposed power factor compensation system is applied to an industrial field, a power factor compensation performance can be maximized. As a result, it is possible to reduce of electricity prices, reduce of line loss, increase of load capacity, ensure the transmission margin capacity, and reduce the amount of power generation.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1107-1111
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• 2004

As an information technology is developed, more intelligent system considering emotional factor for implementing the personality is required. In this paper, Reactive Learning Inference System considering emotional factor is proposed. Emotional Facter(E) is defined for a criterion for representing the personal preference. This system is designed to have functions of Reactive filtering by Emotional factor, Incremental learning, perception & inference and knowledge retrieval. This system is applied to the area for analysis of customer's tastes and its performance is analyzed and compared.

• Journal of Arbitration Studies
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• v.27 no.1
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• pp.161-182
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• 2017

The purpose of this study is to investigate the factors of conflict formation, conflict resolution type, and relationship performance between convenience store franchise headquarters and franchise stores operated by the franchise system located in the metropolitan area. The conclusion could be summarized as follows. First, according to factor analysis based on the previous research, the factor of conflict between convenience store headquarters and franchisee was tied to three factors such as goal disagreement, doctrinal discrepancy, and interdependence, whereas conflict resolution type was linked to three factors such as cooperation type, attack type, and avoidance type. Finally, the relationship performance is tied to three factors: financial performance, long-term cooperation, and non-financial performance. Second, as a result of Hypothesis 1, the interdependence was positively correlated when the cooperative type was the dependent variable. The target discrepancy was significantly positive(+) when the aggressive type was the dependent variable. The interdependence was significantly negative(-) when the avoidance type was the dependent variable. There also was a significantly positive(+) relationship in the target disagreement. Third, for Hypothesis 2, it is shown that target inconsistency is negative(-) for all cases where financial performance, long-term cooperation, and non-financial performance are dependent variables. Fourth, for Hypothesis 3, when the financial performance is the dependent variable, only the cooperative type shows a positive(+) relationship. On the other hand, when the long-term cooperation and the non-financial aptitude are the dependent variables, the cooperative type has a significant positive(+) relationship.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.281-284
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• 2008

Performance evaluation exposing the performance of structure is affected by the material and structural characteristics. these should be necessary for the analysis about the effect of structure performance. Thus, to evaluate the structural performance affected the material properties and structural characteristics, firstly it is conducted the eigenvalues analysis and non-linear static analysis of the structure, secondly it is analyzed the performance influence factor of the structure. The performance influence factors affecting the performance of structure divided into five classes(strength of concrete, longitudinal and transverse reinforcement, aspect ratio, axial force). From the result of analysis about the change of performance influence factor, the more the strength of concrete is increasing, the more the maximum shear force is increasing and the yield displacement is not changed, the more longitudinal reinforce is increasing, the more yield displacement and the maximum basis shear force is increasing, the more the transverse reinforce is increasing, the change of maximum basis shear force is trivial. The yield displacement of structure is increasing and the maximum basis shear force is decreasing by increasing the aspect ratio, the more the axial force increases, the more yield displacement and maximum basis shear force decease.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.944-951
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• 2012

The conventional indexes for describing the GNSS positioning performance such as satellite visibility, dilution of precision (DOP) and signal to noise ratio is very useful in open sky, however, they are not useful in the land road environment. In this paper new index is suggested for describing the GNSS positioning performance for the road environment. The new index is called Sky View based DOP (SVDOP). SVDOP is derived referring the Sky-View-Factor (SVF). The usefulness is analyzed by comparing the SVDOP and SVF in land road environment after the singularity points are selected and SVDOP is calculated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.10
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• pp.779-786
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• 2015

The objective of this study is to propose a new channel shape that improves thermal-hydraulic performance. The existing Zigzag channel has high pressure loss due to flow separation and reverse flow. To improve this disadvantage, partial straight channel is inserted into bended points. Also, the effects of straight channel's length change on heat transfer and pressure loss are analyzed. Thermal-hydraulic performance of the new shape and existing Zigzag channel are quantitatively compared in terms of Goodness Factor. Mass flow rate was changed from $1.41{\times}10^{-4}$ to $2.48{\times}10^{-4}kg/s$. The average volume goodness factor of 1mm straight channel shape was increased by 25% compared to the Zigzag channel.