• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.775-787
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• 2010

Unlike general-purpose CPUs, the GPUs have been specialized as many-core streaming processors, and are frequently replacing the CPUs in an increasing range of computations thanks to their outstanding parallel computing capacity. In order to respond to such trend, NVIDIA has recently issued a new parallel computing architecture called CUDA(Compute Unified Device Architecture), offering a flexible GPU programming environment for GPGPU(General Purpose GPU) computing. In general, when programmers use the CUDA API, they should clearly understand many aspects of GPU's computing architecture to produce efficient parallel software. In this article, we explain several optimization techniques for CUDA programming that we have verified through a lot of experiment and trial and error, and review how those techniques affect the performance of code execution. In particular, we use a specific problem as an example to analyze several elements that affect performances, such as effective accesses to hierarchical memory system, processor occupancy, and latency hiding. In conclusion, we present several directions that may be utilized effectively in CUDA-based parallel programming.

• Asia Marketing Journal
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• v.14 no.3
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• pp.7-26
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• 2012

The success story of E-mart fascinated many academics and practitioners alike. Though E-mart began as a nameless discount store in Chang-dong, Seoul in 1993, it has transformed itself into a leading distribution company and one of the most powerful brands in Korea. Surprisingly, it achieved the great success against the two crises it met: the national economic crisis and the invasion of the global giant Walmart. The main objective of this case study is to formally examine how E-mart overcame the two crises. More specifically, this case study highlights the ways with which E-mart turned those difficulties into opportunities for growth. In our examination of the E-mart case, we could clearly see E-mart's competence and spirit that allowed it to turn crises into advantageous opportunities. E-mart attracted the customers who wanted value-oriented consumption by its positioning as the "Lowest price discount store", when consumer sentiment was frozen under the economic crisis. Furthermore, when a large-scale foreign discount store like Walmart entered the Korea market, E-mart built its core competencies as the 'Korean style discount store'. These ingenious positioning and efforts resulted in E-mart taking over their archrival, Walmart, and forced the global Goliath to exit the Korean market. The case of E-mart's effective crisis management teaches many important lessons and a few core lessons that apply to many companies. One such lesson is the importance of positioning which enabled E-mart to turn crises into opportunities. Granted, the strategy of positioning as the 'Korean style discount store', or 'Lowest price discount store' was possible due to overall support with cost reduction, development and management of their own system, an apprentice educate system, etc. based on an excellent selection of location of the store and efficient distribution systems. Still, the positioning strategy of E-mart was truly ground breaking in distancing itself from its competitors. The lessons from E-mart will help those companies currently in a stagnant situation or a crisis to turn their obstacles into great success.

• Journal of Technologic Dentistry
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• v.31 no.2
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• pp.45-52
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• 2009

Esthetic restorations have been widely used in dental practice, although many studies have focused on the development and improvement of all ceramic restorations. The success of esthetic restorations depends primarily on an optimal bond strength between various veneered ceramics and core materials for esthetic restorations. The purpose of this study was to compare the shear bond strength between various veneered ceramics and core materials for esthetic restorations. 30 metal cores and 20 zirconia cores were fabricated and divided into five groups according to veneered ceramic materials such as Creation porcelain powder, Cercon Ceram Kiss, and IPS e.max ZirPress. Thirty spacimens were prepared using Creation porcelain powder, veneered 3mm height and 3mm in diameter, over the metal cores (n=10). Twenty specimens were prepared using Cercon Ceram Kiss and Zirpress, veneered 3mm height and 3mm in diameter, over the zirconia cores (n=10). The shear bond strength test was performed in a universal testing machine with a crosshead speed of 1mm/min. Ultimate shear bond strength data were analyzed with One-way ANOVA and the Scheffe's test (p=.05). Within the limits of this study, the following conclusions were drawn: The mean shear bond strengths (MPa) were: 18.44 for Uni metal VH/Creation (NCUC); 18.72 for Heraenium/Creation (NCHC); 16.23 for Wirobond C/Creation (NCWC); 13.88 for Zirconia core/$110{\mu}m$ $Al_2O_3$ sandblasting/Cercon Ceram Kiss (ZS110P); 14.61 for Zirconia core/No surface treatment/IPS e.max ZirPress (ZNTH). The mean shear bond strength for NCUC (Uni metal VH/Creation), NCHC (Heraenium/Creation) and NCWC (Wirobond C/Creation) were significantly superior to ZS110P (Zirconia core/$110{\mu}m$ $Al_2O_3$ sandblasting/Cercon Ceram Kiss) and ZNTH(Zirconia core/No surface treatment/IPS e.max ZirPress) (p<0.05).

• Korean Security Journal
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• no.25
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• pp.109-130
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• 2010

As many countries in the world including the Republic of Korea have used all their national resources in the accelerating economic information warfare, illegal leakage of industrial technologies and information has increased rapidly. The costs required for damage prevention from 2007 to 2008 are estimated at approximately KRW 180 trillion which is expected to increase gradually in future. Because the tricks of leaking key technologies are also getting increasingly systematized, sophisticated and bigger, e.g., simple theft at the individual level or the conspiracy of all the staff taking part in the research activities, we should pay special attention to technology security in addition to technology development. While there are several factors affecting such the brain drain, they usually include personal, social, political and cultural factors, for instance, very heavy educational expenditure of children compared to relatively low pay, the speedy labor market circulation for experienced personnel, or political restrictions on researches. In this context, as part of efforts made to prevent the outflow of core personnel, individual companies and research institutes should establish systematically appropriate core personnel management systems for their own organizational or business goals and principles which are intented to ensure to give better treatment and benefit to core personnel and to exercise closer supervision over them. Furthermore, the conventional personnel management system should be radically and flexibly improved in the manner of encouraging the core personnel returning to the organization to combine their external experiences with practices, instead of penalizing them. At the same time, it is necessary to train and educate core personnel through mutual collaboration and in-house training facilities as well as external academic programs operated jointly at the level of the industry. Finally, as the issues concerning the outflow of core personnel are not just problems of relevant companies and other advanced countries have devoted their best efforts to secure their own key technologies at the national level, it is urgent for the industry and the competent authorities to cooperate closely.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.549-567
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• 1994

Restoration of severly damaged teeth after endodontic treatment had been an interest to many dentists, and it is a fact that there have been lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the influence of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper incisor have severly damaged, so, after the root canal therapy, 4 types of restoration had been carried out; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with composite resin core only, 3) after setting up the Para-Post; restore with amalgam core, then cover with the PPM crown 4) after setting up the Para-Post, restore with composite core, then cover with the PPM crown. After restoration, in order to observe the concentration of stress at internal portion of the teeth and the sourrounding periodontal tissue, developing a 2-dimensional finite element model of labiopalatal section, then loading forces from 3 direction - direction of 45 degrees from lingual side near the incisal edge, horizontal direction from labial height of contour, vertical direction at the incisal edge-were applied. The analyzed results were as follows: 1. Stress of the normal central incisor was concentrated on the dentin aroundpulp chamber, labiocervical portion of a tooth and root apex, but with the alveolar bone, in the case of load from the direction of 45 degrees from lingual side near the incisal edge showed remarkable concentration of stress: 2. Coronal-radicular amalgam technique -showed less concentration of stress on the root and surrounding periodontal tissue than the restoration with the Para-Post. 3. The von Mises equivalent stress on the Para-Post showed maximum value at root-core junction rather than both ends and model with PPM restoration with amalgam core showed the least concentration of stress. Only the force from horizontal direction showed large shear stress on internal portion of the root, root apex and alveolar bone. 4. PPM crown with composite core rarely showed the concentration of stress on root and periodontal tissue. 5. As for alveolar bone, remarkable shear stress was concentrated on labial and palatal side by horizontal load.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.576-582
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• 2018

At present, universities in Korea are trying to raise the competency of university students by preparing them with abilities and attitudes required in society, and many universities are carrying out "core competency based education." Therefore, there is a need to evaluate the core competencies of students and verify educational performance. M University, which trains students in specialized marine topics, also conducts core competency based education, reflecting the specificity of the university. The purpose of this study was to develop and validate a tool to measure the core competencies of M University students. First, preliminary questions were developed based on a literature review. Second, item analysis and exploratory factor analysis were conducted. As a result, six factors were identified. Finally, a total of 50 items were extracted from the final test, and validity was confirmed. The scale developed on the basis of this study can not only diagnose the core competency of students overall but also connect programs by diagnosing individual core competencies. It will be possible to use these results as basic data for honing the differentiated talents of universities specialized in maritime and ocean-related topics.

• Korean Journal of Remote Sensing
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• v.20 no.4
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• pp.245-252
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• 2004

The mechanism of cold core eddy formation was investigated using boundary conditions between the East China coastal cold water and the Kuroshio Warm Current, wind data related to the monsoon which was measured by QuikSCAT, and the bottom topography of the East China Sea. When winds blow from the southeast at an intensity comparable to that in the winter period in 1999 and 2003, the warm Kuroshio and Tsushima Current became stronger, and temperatures were considerably higher than those of the extended cold water of the coast of the East China. At that time, the cold water was captured by warm water from the Kuroshio and the Tsushima Current. This facilitated the formation of mesoscale cold core eddies with diameter of 150km in the East China Sea in May, 1999 and February, 2003. The cold core eddy which was detected by NOAA, SeaWiFS and QuikSCAT satellites. The East China Sea is considered to be important not only as a good fishing ground but also nursery and spawning area for many kinds of fishes. Therefore, it would be worth studying spatio-temporal variations of the cold core eddy in the environmental conditions of the northwestern East China Sea using systematic remote sensing techniques.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.690-692
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• 2012

This pape presents the efficient test data compression method considering test power dissipation in scan test of IP core. There are many researches about test data compression using scan slice selective encoding except power dissipation. We present the new algorithm that assigns the don't care value to be a minimal hamming distance between adjacent slices. Experimental results show that the power dissipation is reduced.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.394-394
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• 2016

The oxygen reduction reaction (ORR) in a polymer electrolyte membrane (PEM) fuel cell requires the use of Pt-based catalysts. Due to the high cost and low abundance of Pt, many researchers have been studied to reduce the use of Pt while to enhance the catalytic performance of Pt. One of the promising strategies is the deposition of Pt as ultrathin skins of only a few atomic layers on nanoscale substrates made of another metal. This presentation will discuss the conformal deposition of Pt as uniform, ultrathin shells on Pd nanocrystals. By optimizing the catalytic behavior of Pt-based nanocrystals, we obtained the greatly enhanced ORR activity and durability.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.127-133
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• 2006

Recently, various building types such as Center-Core shape and Y-shape were studied as the demand for hight-rise residental complex increased. However, Center-Core type can make many Problems because the house unit can face to the north or west. Therefore, this study evaluated daylight conditions for four plan types in high-rise residental complex.