• International Journal of Naval Architecture and Ocean Engineering
• /
• v.7 no.1
• /
• pp.195-211
• /
• 2015

Flat plate friction lines have been used in the process to estimate speed performance of full-scale ships in model tests. The results of the previous studies showed considerable differences in determining form factors depending on changes in plate friction lines and Reynolds numbers. These differences had a great influence on estimation of speed performance of full-scale ships. This study was conducted in two parts. In the first part, the scale effect of the form factor depending on change in the Reynolds number was studied based on CFD, in connection with three kinds of friction resistance curves: the ITTC-1957, the curve proposed by Grigson (1993; 1996), and the curve developed by Katsui et al. (2005). In the second part, change in the form factor by three kinds of friction resistance curves was investtigated based on model tests, and then the brake power and the revolution that were finally determined by expansion processes of full-scale ships. When three kinds of friction resistance curves were applied to each kind of ships, these were investigated: differences between resistance and self-propulsion components induced in the expansion processes of full-scale ships, correlation of effects between these components, and tendency of each kind of ships. Finally, what friction resistance curve was well consistent with results of test operation was examined per each kind of ships.

• Journal of Korea Foundry Society
• /
• v.31 no.4
• /
• pp.205-211
• /
• 2011

Al-Si alloys have been steadily used as a potential material for the achievement of an efficient weight reduction in the automobile and aerospace industries due to its excellent castability and high strength-to-weight ratio. In this study, riser effect and mechanical properties were investigated according to the size of the sleeve. In addition, the effects of riser size on mechanical properties of castings were investigated. On the other hand flow and solidification process were simulated with a hybrid FDM/FEM package named ZCast. As a result, results of simulation and experiments were comparable regarding to the yield strength, tensile strength, elongation and hardness of casting. It proves the reliability of the simulation. It is expected that the proper size of riser can improve the recycling rate of metallic materials and reduce the cost of casting.

• Journal of Arbitration Studies
• /
• v.14 no.1
• /
• pp.185-211
• /
• 2004

It is a common and prevailing Construction that recent environmental problems such as earth's warmer climate and depletion of ozone layers can never be solved by the efforts of any one nation. That is why the international conventions have been held more often lately in order to discuss the matter of environment protection and there has been increased tendency of using economic activities of any nation especially their international trades as means for achieving the purpose of environment protection. Furthermore, there is an ample possibility for the advanced countries to use the regulatory restrictions for environment protection as an another measure of none-tariff barrier against countries including Korea which has high dependence on international trade with not very high technological capability of environment protection. Some of the developed countries have recently moved toward the creation of a new system of international regulatory measures on world trade in the name of Environment Protection. They Plan to impose strict control over the process and technology of production of good they are importing from other country. However, ever though the international regulatory measures, in a short term, could play a negative role on our trade capability, they could, in the long run, also play a role of helping hands if we usefully work out positive countermeasures as a result of hand-working government supported by industry and all the society as a whole.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.39 no.3
• /
• pp.211-219
• /
• 2002

In this paper, a new architecture that can simultaneously process modular multiplication and squaring on GF(2$^{m}$ ) in m clock cycles by using the cellular automata is presented. This can be used efficiently for the design of the modular exponentiation on the finite field which is the basic computation in most public key crypto systems such as Diffie-Hellman key exchange, EIGamal, etc. Also, the cellular automata architecture is simple, regular, modular, cascadable and therefore, can be utilized efficiently for the implementation of VLSI.

• Composites Research
• /
• v.28 no.4
• /
• pp.204-211
• /
• 2015

This paper presents a theory related to a two-dimensional linear cross-sectional analysis, recovery relationship and a one-dimensional nonlinear beam analysis for composite wing structure with initial twist. Using VABS including a related theory, the design process of the composite rotor blade has been described. Cross-sectional analysis was performed at cutting point including all the details of geometry and material. Stiffness matrix and mass matrix were linked to each section to make 1D beam model. The 3D strain distributions within the structure were recovered based on the global behavior of the 1D beam analysis and visualize numerical results.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.16 no.2
• /
• pp.211-225
• /
• 2014

Globalization in the 21st century and development in the field of IT have caused rapid change in the practical site of fashion industry. Therefore, as colleges aim to produce professional technicians and experts in the applicable fields, they are strengthening professionalism and practicality more than ever before that can respond to the practical situation. In addition, owing to the reduction of population of academic students, colleges would search for specialty and structural innovation with the serious desire to establish new structural system to produce talented persons. Purpose of this study is to strengthen competition of colleges voluntarily, specialize themselves and maximize mutual benefit through cooperative relation with industrial businesses. Thus, this study would compare, analyze and investigate the curriculums of fashion designs in colleges for the plan of curriculum applicable for the industrial changes and corresponding business demand. Considering the result of questionnaires of industrial businesses, most of them would prefer the curriculum for 3 years to that for 2 years. Nowadays industrial businesses will require computerization ability much more than ever before besides the professional knowledge and technology in the field of fashion and it is also showed that education of personality in colleges would be considered to be important for the performance of the vocational duty. Especially, specialty and progressive participation in the curriculum would be strengthened during the education process of colleges. This study will be used for the establishment of specialty of colleges and development of curriculum of them.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.11a
• /
• pp.211-216
• /
• 1997

ZnO and A1$_2$O$_3$ powders were mixed in 1 : 1 mole ratio and ball-milled with ethanol for 3 h. After the pressing process, the mixtures were sintered at $700^{\circ}C$~130$0^{\circ}C$ for 5 h in air to form ZnA1$_2$O$_4$. Structural properties were analyzed by X-ray diffraction patterns ; optical properties by absorption spectra with UV-VIS-H[R Spectrophotometer ; microstructural properties by SEM ; photoluminescent properties by using PL Measuring System. In result, ZnAl$_2$O$_4$ phosphor is crystallized at 110$0^{\circ}C$ and optical bandgap is calculated at 4.65 eV. PL spectrums were shifted to longer wavelengths with increasing temperature and was appeared around 780nm at 130$0^{\circ}C$ . Additionally, the peak intensity was veil strong at 80$0^{\circ}C$ and was declined with increasing temperature.

• Journal of the Korea Furniture Society
• /
• v.18 no.3
• /
• pp.211-223
• /
• 2007

21 Century is said the age of cultural industry. In this cultural Industry one of very important factors which guides this times is the exploitation of cultural goods, which is based on regional identity. Therefore, at this point of time when its weighty has been raised, the aim of this study is to fill the image Korean tradition and modernity culture in them, through the search on their characteristics among regions and nations, desk the cultural service goods which gets survival power of traditional and cultural identity. Nine existing Hahoe masks are changed into nine new cultural items, which are presented the nine dreams of Hahoe masks. As consumer's choice is diversified by a set of products, main concept in this study is the focus on modernity, rationality, traditionality and popularity. The main concept of this study is on rational functions and convenience, the harmony of tradition and modernity. As said above, in the process of manufacture the mass production of goods is stressed, and by getting the composition and making a set of goods, the choice of consumers will be extended. Getting ideal globalization by the coexistence of tradition and modernity on goods, is very important. Consequently, cultural goods must be recognized as a factor of its medium, and also, on domestic cultural goods people's interest must be risen all the more.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 1999.11a
• /
• pp.211-215
• /
• 1999

It is well known that a long-term exposure to a loud noise environment affects performance, since it distracts attention, and also is able to evoke stress accompanied by negative emotional states. The purpose of this study was to analyze dynamics of subjective and physiological variables during long-lasting (30 min) exposure to intensive white noise (85 dB[A]). Physiological signals on 23 college students were recorded by BIOPAC, Grass Neurodata systems and AcqKnowledge 3.5 software. Autonomic variables, namely skin conductance level (SCL), non-specific SCR number (N-SCR), inter-beat intervals in ECG (RR intervals), heart rate variability index (HF/LF ratio of HRV), respiration rate (RESP), and skin temperature (SKT) were analyzed on 5 min epoch basis. Psychological assessment (subjective rating of stress level) was also repeated on every 5 min basis. Regression and correlation analyses were employed to trace the time course of the dynamics of the subjective and autonomic physiological variables and their relationship. Results showed that intense noise evokes subjective stress with associated autonomic nervous system responses. However, it was shown that physiological variables endure specific changes in the process of exposure to loud white noise. Discussed are probable psychophysiological mechanisms mediating reactivity to long-term auditory stimulation of high intensity.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.2
• /
• pp.211-220
• /
• 2011

The diagrid structure is now one of the trends in tall-building structures. It is preferred not only because of its distinctive appearance but also because of its structural advantages. There are few diagrid buildings that actually exist, however, because of the nodes, which are difficult to make and cost too much. In this study, a node-type diagrid building material with a more efficient structure but with fewer diagrid nodes, fabricated using the finite element method, was proposed and validated via experimentation.