• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.31-36
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• 2016

User authentication is the first step to network security. There are lots of authentication types, and more than one authentication method works together for user's authentication in the network. Except for biometric authentication, most authentication methods can be copied, or someone else can adopt and abuse someone else's credential method. Thus, more than one authentication method must be used for user authentication. However, more credential makes system degrade and inefficient as they log on the system. Therefore, without tradeoff performance with efficiency, this research proposed user's behavior based authentication for secure communication, and it will improve to establish a secure and efficient communication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.2963-2978
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• 2017

The Top-K query is currently played a key role in a wide range of road network, decision making and quantitative financial research. In this paper, a Top-K recommendation algorithm is proposed to solve the cold-start problem and a tag generating method is put forward to enhance the semantic understanding of the OLAP session. In addition, a recommendation system for OLAP sessions called "OLAP4R" is designed using collaborative filtering technique aiming at guiding the user to find the ultimate goals by interactive queries. OLAP4R utilizes a mixed system architecture consisting of multiple functional modules, which have a high extension capability to support additional functions. This system structure allows the user to configure multi-dimensional hierarchies and desirable measures to analyze the specific requirement and gives recommendations with forthright responses. Experimental results show that our method has raised 20% recall of the recommendations comparing the traditional collaborative filtering and a visualization tag of the recommended sessions will be provided with modified changes for the user to understand.

• Journal of Information Technology Applications and Management
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• v.27 no.1
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• pp.97-109
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• 2020

It is expected that the Fourth Industrial Revolution will have a great impact on the manufacturing industry, especially as it will cause big changes in industry, economy as well as socio-cultural. To cope with this situation, each country is promoting the policy of cultivating its manufacturing. This study derives the effect of the fourth industrial revolution on product lifecycle management for smart manufacturing through expert's cognitive analysis. The knowledge area of product lifecycle management is divided into Project Portfolio Management, Collaborative Product Design, Customer Needs Management, Direct Material Sourcing, Product Data Management, Digital Manufacturing & Engineering, R&D Foundation, New Product Development through academic research. The expert survey was conducted in five different perspectives: Importance, Insufficiency. Then, using the results of the survey and the academic research the implication about Product Lifecycle Management were derived. The significance of this study is that it derives the change areas and factors of the product life cycle management knowledge domain in preparation for the fourth industrial revolution according to the perspective of importance and insufficiency.

• Journal of Animal Environmental Science
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• v.4 no.1
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• pp.47-53
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• 1998

The purpose of this study was to investigate the change of temperature, moisture content, weight and chemical properties in swine manure during the maturing process and moisture content of swine manure. The manure production on the early time(1 days), middle(25 days: and late(50 days) were made by moisture 45%, 55%, 65%, 75% in swine manure, according to manure treatment of the early time, the highest temperature of swine manure treatment was 59$^{\circ}C$ as moisture 75% after mixed 24 hours, the lowest 45% in mixed 25 days(middle time), 32$^{\circ}C$ as moisture 45% in mixed 50 days(late time). 2. Weight change during maturing manure, the most treatment of weight decrease was 17.4% as moisture 45%, the least of those was 12.2% as moisture 75% during maturing process of swine manure. 3. Volume change during maturing manure, the most treatment of volume decrease was 37.1% as moisture 65%, the least of those was 32.1% as moisture 55% during maturing swine manure, but not big difference between treatment. 4. T-N, P2O5, K2O content of compost were increased during maturing process, On the contrary, T-C content and C/N ratio were reduced.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.608-612
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• 2012

To reduce these costs and time by finite element analysis program has been much research (3~4). At virtual CAE program as like Abaques, Ansys, Ls-dyna and Nastran, the input data of material is got bellow coupon test. In case of carbon composite, it is also put in lamina/laminate properties. There have big problem. If you want to simulate FW(filament winding or wind blade) how do you input material data. Each area of FW is different stacking conditions. It's too hard that each area is tested for inputting lamina or laminate properties. The composite structure increasing load is applied occurred as the matrix dependence of the crack-induced nonlinearity and nonlinear mobility appears since the initial damage. And uni-direction for this research applies the theory to have been confined to. On this study, we are going to get basically fiber properties and matrix than carbon composite properties for simulating according stacking method by GENOA-MCQ. It is help to simulate easily composite material. Also Calculate the matrix nonlinear for simulating non-linear.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.1
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• pp.35-53
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• 2016

The purpose of this study is for investing and analysing preservice elementary mathematics teachers' efficacy on teaching mathematics. It was measured by Kang & Kim(2014)'s instrument; MTEI (Mathematics Teaching Efficacy Instrument). The survey was conducted on a sample of 164 participants who are the 2 or 4 grade in 3 universities of education. The findings of this study are that mathematics teaching efficacy of preservice elementary mathematics teachers in South Korea is 61 percent based on 100 percent. There was no significant difference between women teachers and men teachers, department of natural science and art & humanity when highschool, 2 grade and 4 grade. But, there was the significant difference between big city and province. The social-cultural factor point was much lower than any other factors' point.

• Journal of Fashion Business
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• v.21 no.4
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• pp.44-60
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• 2017

This study is to understand the image of the Korean beauty and rewards to be gained by trying to be a beautiful person and to study differences according to demographic characteristics. It was studied with the purpose of industrializing beauty image and selling it to foreign countries. The survey questionnaire was distributed to Seoul and Kyeongkido. Respondents totaled 301. Collected data were analyzed with frequency analysis, factor analysis, $X^2$-test, and regression. Results are ; (1) The external image of Korean beauty emphasizes round face, white skin, big eyes, double eyelids, round head shape, early twenties, tall, low body weight, thin waist, long neck, long legs, and thin fingers. (2) The inner image of the Korean beauty emphasizes mature personality, social economic ability, but not housework, and cultural artistic ability. (3) Rewards gained by trying to be a beauty are psychological, actual, and social ones. (4) External face and body image of the beauty are different by demographic characteristics (sex, age, marital status, final education, monthly average income, religion). (5) The inner image of the beauty is different by age, final education, and monthly average income. (6) Rewards gained by trying to be a beauty are different by sex, age, final education, and monthly average income.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.2 s.13
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• pp.13-18
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• 2004

In this study, in the first place, parameters primarily influencing displacement and stress were constructed by using the Finite Difference Method; then using those parameters, the result of crown displacement and convergence among the existing, experimental values of a centrifuge model were compared with the result of numerical analysis; and then considering the stress and time effect of lining installation, parameters according to the difference of stiffness were studied. In the result of this study, it found out that rough, ground reinforcement effect manifests itself when reinforcement propert of the grouting of the big scale steel pipe through 3-D analysis is E= 4,000tf/m2 which of the stiffness of the original ground.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.402-409
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• 2011

Compatibility and properties of PP/N66 blends with or without PP-g-MAH as a compatibilizer were investigated by DSC, SEM and universal testing machine. Morphological studies revealed that PP and N66 were incompatible and addition of PP-g-MAH was very effective to enhance the compatibility between PP and N66. The compatibilization effect between N66 and PP-g-MAH was based on the reaction between the amine end group of N66 and anhydride group in PP-g-MAH. The crystallization and melting behavior of PP/N66 blends were investigated and the results of analyses for enthalpy changed were discussed. The Izod impact strength could be improved by optimizing the compatibilizer concentration. Tensile strength, elongation at break, notched Izod impact strength were increased with using compatibilizer, however, both the compatibilized and the noncompatibilizer blends did not show any big difference in the flexural modulus.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.427-435
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• 2011

This paper deals with the measurement and analysis of the squeal noise according to the curvature of rail. The squeal noise is generated by the friction between the railway with curve and the wheel. The squeal noise is a big problem in Busan Metro Line 3. If the developing panel type ANC(Active Noise Control) system which is attached to the floor can reduce 5 dB in below 500 Hz, the sound pressure level of the whole band pass can be reduced about 4-4.8 dB in squeal noise above the curvature of R400. Curve squeal noise is the intense high frequency tonal that can occur when a railway vehicle transverses a curve. The frequency range is from around 500 to almost 20,000 Hz, with noise levels up to about 15 dB in curve.