• Journal of Korea Foundry Society
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• v.40 no.2
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• pp.34-42
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• 2020

The effects of the initial balancing pressure, filling pressure and maximum build-up pressure on the casting characteristics of the thick-wall thickness casting during the counter-pressure casting process were investigated. Water model experiment and a computer simulation were carried out to evaluate the characteristics during the filling and solidification stages in counter-pressure casting (CPC); as a reference, the low-pressure casting (LPC) process was used. The average dendrite cell size decreased with an increase in the solidification rate and maximum build-up pressure. A turbulent flow occurred during the filling stage of the LPC process, resulting in the formation of inner gas, while a lamellar flow pattern dominated during the CPC process and was more evident with an increase in the initial balancing pressure, improving the mechanical properties of the castings.

• The Research Journal of the Costume Culture
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• v.21 no.4
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• pp.585-595
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• 2013

The most researches developing pattern of compression style sportswear were targeted at the live model that has muscular body build. The purpose of this study was developing a method for classifying men's lower body types in terms of muscular body build. The 3D human body scan data and body measurements of 30s of Size Korea were analyzed. The subjects (n=203) were men between the ages of 30 and 39 years. Men's muscular body build was classified with two key dimensions, thigh girth and calf girth. The subjects were divided into four groups. From each group, average subjects (n=42) whose height and weight were close to the mean value ($mean{\pm}1/2$ S.D.) were selected. 42 subjects were divided up as four groups. Group I (n=7) was thigh and calf developed body type. Group II (n=9) was thigh developed body type. Group III (n=11) was calf developed body type. Group IV (n=15) was thigh and calf undeveloped body type. Four groups had distinct different at widths (n=4), depths (n=4), and girths (n=9) dimensions. The results showed that the muscular men in their 30s could be defined by thigh and calf girths. The thigh developed muscular men had thigh girth over 60cm and the calf developed muscular men had calf girth over 38cm. From each group one representative was selected by 3D body scan figure.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.314-314
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• 2010

For the optimal design of a tokamak-type reactor, self-consistent determination of a radial build of reactor systems is important and the radial build has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor systems. In a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil, the shield should provide sufficient protection for the superconducting TF coil and the shield plays a key role in determining the size of a reactor. To determine the radial build of a reactor, neutronic effects such as tritium breeding in the blanket, nuclear heating, and radiation damage to toroidal field (TF) coil has to be included in the systems analysis. In this work, the outboard blanket only is considered where tritium self-sufficiency is possible by using an inboard neutron reflector instead of breeding blanket. The reflecting shield should provide not only protection for the superconducting TF coil but also improved neutron economy for the tritium breeding in outboard blanket. Tungsten carbide, metal hydride such as titanium hydride and zirconium hydride can be used for improved shielding performance and thus smaller shield thickness. With the use of advanced technology in the shield, conceptual design of a compact superconducting LAR reactor with aspect ratio of less than 2 will be presented as a viable power plant.

• Korean Journal of Materials Research
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• v.18 no.3
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• pp.117-122
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• 2008

Micro-sized bumps on a multi-layered build-up PCB were fabricated by pulse-reverse copper electroplating. The values of the current density and brightener content for the electroplating were optimized for suitable performance with maximum efficiency. The micro-bumps thus electroplated were characterized using a range of analytical tools that included an optical microscope, a scanning electron microscope, an atomic force microscope and a hydraulic bulge tester. The optical microscope and scanning electron microscope analyses results showed that the uniformity of the electroplating was viable in the current density range of $2-4\;A/dm^2$; however, the uniformity was slightly degraded as the current density increased. To study the effect of the brightener concentration, the concentration was varied from zero to 1.2 ml/L. The optimum concentration for micro-bump electroplating was found to be 0.6 ml/L based on an examination of the electroplating properties, including the roughness, yield strength and grain size.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.7
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• pp.3714-3732
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• 2019

With the rapid development of network, Intrusion Detection System(IDS) plays a more and more important role in network applications. Many data mining algorithms are used to build IDS. However, due to the advent of big data era, massive data are generated. When dealing with large-scale data sets, most data mining algorithms suffer from a high computational burden which makes IDS much less efficient. To build an efficient IDS over big data, we propose a classification algorithm based on data clustering and data reduction. In the training stage, the training data are divided into clusters with similar size by Mini Batch K-Means algorithm, meanwhile, the center of each cluster is used as its index. Then, we select representative instances for each cluster to perform the task of data reduction and use the clusters that consist of representative instances to build a K-Nearest Neighbor(KNN) detection model. In the detection stage, we sort clusters according to the distances between the test sample and cluster indexes, and obtain k nearest clusters where we find k nearest neighbors. Experimental results show that searching neighbors by cluster indexes reduces the computational complexity significantly, and classification with reduced data of representative instances not only improves the efficiency, but also maintains high accuracy.

• Journal of radiological science and technology
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• v.41 no.1
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• pp.13-24
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• 2018

Liver size is an important component in the diagnosis and follow-up of diffuse liver disease when testing for liver disease using ultrasonography. However, difficulties lies in determining the presence of hepatomegaly and liver atrophy because the method used for measuring liver size differs from one examiner to another and there is no relevant standard based on body build. The present study aims to propose a more objective method for liver size measurement and a reference range based on body build. A total of 260 normal adults (130 males, 130 females) participated in the study. Ultrasonography was performed in all participants to measure the size of the right lobe, left lobe, quadrate lobe, and caudate lobe of liver. Based on Physique Index(PI), a value derived from multiplying weight(kg) by height($m^2$), size of physique was divided into three groups including Group I with PI<150, Group II with $150{\leq}PI{\leq}250$, and Group III with PI>250. Thus, mean liver size by PI and a reference range with 95% reliability were suggested. The superoinferior diameter of right lobe was $12.34{\pm}1.18cm$ in males and $11.07{\pm}0.93cm$ in females, and its reference range was 10.64~11.0cm for Group I, 11.78~12.12cm for Group II, and 13.02~13.84cm for Group III. The anteroposterior diameter(T) of left lobe was $5.93{\pm}1.09cm$ in males and $5.18{\pm}0.99cm$ in females, and its reference range was 4.77~5.17cm for Group I, 5.49~5.79cm for Group II, and 6.68~7.44cm for Group III. The transverse diameter was $3.51{\pm}0.60cm$ in male participants and $3.42{\pm}0.49cm$ in female participants and its reference range was 3.29~3.51cm for Group I, 3.36~3.55cm for Group II, and 3.52~4.0cm for Group III. The caudate lobe index was $11.65{\pm}2.88cm^2$ in males and $9.62{\pm}2.18cm^2$ in females and its reference range was $8.83{\sim}9.75cm^2$ for Group I, $10.62{\sim}11.47cm^2$ for Group II, and $11.89{\sim}14.26cm^2$ for Group III. As a basic measurement method of liver size, the present study suggests measuring the superoinferior diameter for right liver lobe, the anteroposterior diameter for left liver lobe, the transverse diameter for quadrate lobe, and the caudate lobe index for caudate lobe. It is expected that this method along with its relevant reference range can be used as useful indicators in determining hepatomegaly and liver atrophy upon the diagnosis and follow-up testing of diffuse liver disease.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.185-189
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• 2008

Practical pattern recognition systems should overcome very large class problem. Sometimes it is almost impossible to build every model for every class due to memory and time constraints. For this case, grouping similar models will be helpful. In this paper, we propose GMC(Group Model Clustering) to build a large class Chinese character recognition system. We built hidden Markov models for 10% of total classes, then classify the rest of classes into already trained group classes. Finally group models are trained using group model clustered data. Recognition is performed using only group models, in order to achieve reduced model size and improved recognition speed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.582-582
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• 2012

Characteristics of a fusion-driven transmutation reactor was investigated. A compact reactor concept is desirable from an economic viewpoint. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components. In a transmutation reactor, design of blanket and shield play a key role in determining the size of a reactor; the blanket should produce enough tritium for tritium self-sufficiency, the transmutation rate of waste has to be maximized, and the shield should provide sufficient protection for the superconducting toroidal field (TF) coil. To determine the radial build of the blanket and the shield, not only a radiation transport analysis but also a burnup calculation were coupled with the system analysis and it allowed the self-consistent determination of the design parameters of a transmutation reactor.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.95-101
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• 2013

MANET has an advantage that can build a network quickly and easily in difficult environment to build network. In particular, routing protocol that uses in existing mobile environment cannot be applied literally because it consists of only mobile node. Thus, routing protocol considering this characteristic is necessary. Malicious nodes do extensive damage to the whole network because each mobile node has to act as a router. In this paper, we propose technique that can detect accurately the suspected node which causes severely damage to the performance of the network. The proposed technique divides the whole network to zone of constant size and is performed simultaneously detection technique based zone and detection technique by collaboration between nodes. Detection based zone translates the information when member node finishes packet reception or transmission to master node managing zone and detects using this. The collaborative detection technique uses the information of zone table managing in master node which manages each zone. The proposed technique can reduce errors by performing detection which is a reflection of whole traffic of network.

• Industrial Engineering and Management Systems
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• v.12 no.2
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• pp.118-129
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• 2013

In this study, we intend to identify key financial variables that can accurately classify Green IT leaders against Green IT followers. In particular, we build and compare single and meta-classifiers to identify the relationship between environmental performance and financial performance, while focusing on selecting and interpreting a final prediction model with a smaller set of financial performance indicators. Our experimental results demonstrate that several key variables representing the size, financial resources, operational efficiency, and risk-taking tendency of an organization can successfully identify Green IT leaders with approximately 90% of accuracy. In addition, we find that Green IT leaders show a higher utilization rate of Web pages as a green marketing channel than Green IT followers while they share common layouts of Web publication to build green IT brands with some differences.