• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.2
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• pp.327-346
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• 2013

Researchers as well as network providers are increasingly interested in understanding how a network user's experience changes in relation to different quality of service (QoS) parameters, with many attempts being made to identify the general relationship between quality of experience (QoE) and QoS. Several relations in different function forms have been proposed. There are instances when this variety of proposed functions potentially results in one problem having completely dissimilar solutions at the same time. The question then is which function form is the one that can better explain this relationship. In this paper, three major existing quantitative relationships between QoE and QoS are investigated. After conducting a comprehensive comparative analysis between them, a new definition of QoE-QoS dependency appears. It then results in identifying a new mutual relationship between QoE and QoS. The newly proposed relationship improves the deficiency of previous QoE-QoS relationships along with solving the problem of diversity of simultaneous solutions for one problem.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.15-21
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• 2003

In order to improve the quality of a spindle unit it is important to increase its rotational accuracy. The rotational accuracy of a spindle unit can be defined as the stability or immobility of its spindle axis while rotating. Spindle rotation in the rolling bearings causes the disturbing influence, which leads to the oscillation of a rotation axis. The purpose of this study is to investigate the oscillation sources and find a way to decrease the runout without additional expenses. The main source of oscillation is the interaction between rolling bodies and ring races. The first oscillation source was the out-of-shape imperfection of inner bearing ring. The mutual compensation of oscillation by proper rings orientation was proposed, which sometimes allow to decrease the radial runout of spindle rotation axis by approximate 40％ down. Also the outer ring harmonics were explored as the second oscillation source. The analysis shows the dependency between the number of rolling bodies and the outer ring race harmonics. The conclusion on the orientation of bearing cages and the bearing rings was made, which makes possible to obtain the optimal variant of their mounting in the spindle unit when the rotational accuracy of the spindle is maximal, and the spindle runout considerably less.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.4
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• pp.244-249
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• 2014

In this research, it have developed a sensor that could diagnose inner deterioration of covered wires. With this sensor it observed results from simulation, and the attribute required for realization. For simulation it have used FLUX, it have considered all of geometric and electromagnetic information from coil and base metal that influences eddy current sensor's property in order to predict the final result. It assumed there is no mutual inductance in the coil with N number of turns, because equivalent current flows in coil that is continuously connected in eddy current sensor. It assumed circular coil loop draws a circle, always have self inductance, and they are connected in series and overlapped according number of turns (N) in coil, and bobbin configuration. Actual sensor was produced with consideration of inductance and number of turns (N). In conclusion, it were able to test the dependency through results from simulation, actual measurement, and modeling of simulation. It is considered that attributes of respective base metal and structure can be predicted by simulating in advance.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.317-323
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• 2010

Nutrient availability is a critical component of agroecosystems, and is relevant to both above- and below- ground interactions. The principal objective of this study was to determine how the cessation of fertilization affects the communities of weeds and soil organisms in a corn/wheat field. Changes in dominant weed species, substrate-induced respiration, and the population density of nematodes and microarthropods were evaluated. Microbial substrate-induced respiration (SIR) and the population density of microarthropods decreased following the cessation of fertilization and were partly correlated with the aboveground weed biomass. The cessation of organic fertilizer application but continuing application of inorganic fertilizer reduced the population density of nematodes. In response to the cessation of fertilization, weed communities were dominated by species with little dependency on fertilization. Amaranthus retroflexus was identified as the most dominant species in the corn field; however, it was replaced by Digitaria ciliaris after the cessation of fertilization. In the wheat field, the cessation of fertilization led to a rapid reduction in the biomass of most weeds, except for Vicia angustifolia, supposedly as the result of symbiotic nitrogen fixation. Additionally, the fact that weed biomass was partially correlated with SIR or the population density of microarthropods may reflect a mutual feedback between soil organisms and weeds. The results indicate that the cessation of fertilization alters communities of weeds and soil organisms through changes in weed biomass and interactions with symbiotic microorganisms.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.3
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• pp.273-283
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• 2000

In this paper we suggest an optimal design method of Fuzzy-Neural Networks(FNN) model for complex and nonlinear systems. The FNNs use the simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. And we use a HCM(Hard C-Means) Clustering Algorithm to find initial parameters of the membership function. The parameters such as parameters of membership functions learning rates and momentum weighted value is proposed to achieve a sound balance between approximation and generalization abilities of the model. According to selection and adjustment of a weighting factor of an aggregate objective function which depends on the number of data and a certain degree of nonlinearity (distribution of I/O data we show that it is available and effective to design and optimal FNN model structure with a mutual balance and dependency between approximation and generalization abilities. This methodology sheds light on the role and impact of different parameters of the model on its performance (especially the mapping and predicting capabilities of the rule based computing). To evaluate the performance of the proposed model we use the time series data for gas furnace the data of sewage treatment process and traffic route choice process.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.727-729
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• 2005

나이브베이즈분류기($na\ddot{i}ve$ Bayes classifier)는 학습, 적용 및 계산자원 이용의 측면에서 매우 효율적인 모델이다. 또한, 그 분류 성능 역시 다른 기법에 비해 크게 떨어지지 않음이 다양한 실험을 통해 보여져 왔다. 특히, 데이터를 생성한 실제 확률분포를 나이브베이즈분류기가 정확하게 표현할 수 있는 경우에는 최대의 효과를 볼 수 있다. 하지만, 실제 확률분포에 존재하는 조건부독립성(conditional independence)이 나이브베이즈분류기의 구조와 일치하지 않는 경우에는 성능이 하락할 수 있다. 보다 구체적으로, 각 자질변수(feature variable)들 사이에 확률적 의존관계(probabilistic dependency)가 존재하는 경우 성능 하락은 심화된다. 본 논문에서는 이러한 나이브베이즈분류기의 약점을 효율적으로 해결할 수 있는 자질변수의 통합기법을 제시한다. 자질변수의 통합은 각 변수들 사이의 관계를 명시적으로 표현해 주는 방법이며, 특히 상호정보량(mutual information)에 기반한 통합 변수의 선정이 성능 향상에 크게 기여함을 실험을 통해 보인다.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.97-106
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• 1993

This is the study on fracture life under the interaction of creep and fatigue. It is difficult to explain the interaction of the creep and fatigue with indication of frequency but the dependency of the time should be considered. The formulation of material varieties causing by interaction of creep and fatigue is required in the accumulative damage method. The strain range partition method requires some of modification corresponding to the changes in temperature and load. All of other method also comprehended with above mentioned problems. Generally, in this field, the variety of stress-strain and suitable parameter is required and connective study between the macro and micro results seems to be insufficient. The linear damage rule is acquiring the support generally but it requires modification in the hgigh temperature instruments. The variety of stress effecting on crack and variety of stress on the metallurgical side are considered to be problems in the future days.

• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.1-11
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• 2020

With the activation of OTT and VOD services, the viewing behavior is rapidly changing, but the programming regulation has not escaped the ratio regulation in the same way as in the past. Therefore, this paper aims to examine the policy validity of the current organization ratio regulation and to suggest improvement directions based on this. To this end, the policy objectives and background at the time of the introduction of the domestic organization ratio regulation were considered and compared with the current status of the broadcasting market. As a result, this study found that it is difficult to apply the logical framework of asymmetric regulation at the time of the formation ratio regulation into the current status of broadcasting market, the existing framework was established and hold in the mutual relationship of various stake holders formed based on the asymmetric regulation. It was pointed out that the typical pattern of path dependency repeating only fine adjustment of ratio was shown. Based on this, this study suggests that it needs to be divided into the regulation by the public interest and the regulation by the industrial purpose according to the purpose of regulation, and it is necessary to be limited to the direct regulation corresponding to the public interest of the viewer. Also this study proposes that it is necessary to separate the regulation from promotion policies as well as to resolute asymmetric regulation in broadcasting policies.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.7
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• pp.339-349
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• 2001

This paper suggests an optimal identification method for complex and nonlinear system modeling that is based on Fuzzy-Neural Networks(FNN). The proposed Hybrid Identification Algorithm is based on Yamakawa's FNN and uses the simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. In this paper, the FNN modeling implements parameter identification using HCM algorithm and hybrid structure combined with two types of optimization theories for nonlinear systems. We use a HCM(Hard C-Means) clustering algorithm to find initial apexes of membership function. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are adjusted using hybrid algorithm. The proposed hybrid identification algorithm is carried out using both a genetic algorithm and the improved complex method. Also, an aggregated objective function(performance index) with weighting factor is introduced to achieve a sound balance between approximation and generalization abilities of the model. According to the selection and adjustment of a weighting factor of an aggregate objective function which depends on the number of data and a certain degree of nonlinearity(distribution of I/O data), we show that it is available and effective to design an optimal FNN model structure with mutual balance and dependency between approximation and generalization abilities. To evaluate the performance of the proposed model, we use the time series data for gas furnace, the data of sewage treatment process and traffic route choice process.

• Advances in Computational Design
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• v.3 no.4
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• pp.319-338
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• 2018

High-performing architecture should be designed by taking into account the mutual dependency between the new building and the local context. The performative architecture plays an important role to avert any unforeseen failures after the building has been built; particularly ones related to the microclimate impacts that affect the human comfort. The use of the concept of solar envelopes helps designers to construct the developable mass of the building design considering the solar access and the site obstruction. However, the current analysis method using solar envelopes lack in terms of integrating the detailed information of the existing context during the simulation process. In architectural design, often the current site modelling not only absent in preserving the complex geometry but also information on the surface characteristics. Currently, the emerging applications of point clouds offer a great possibility to overcome these limitations, since they include the attribute information such as XYZ as the position information and RGB as the color information. This study particularly presents a comparative analysis between the manually built 3D models and the models generated from the point cloud data. The modelling comparisons focus on the relevant factors of solar radiation and a set of simulation to calculate the performance indicators regarding selected portions of the models. The experimental results emphasize an introduction of the design approach and the dataset visibility of the 3D existing environments. This paper ultimately aims at improving the current architectural decision of support environment means, by increasing the correspondence between the digital models for performance analysis and the real environments (context of design) during the conceptual design phase.