• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.1
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• pp.50-63
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• 2002

The Karman boundary-layer has been numerically investigated for the disturbance wave number, wave velocity, azimuth angle and radius (Reynolds number, Re). The disturbed flow over rotating disk can lead to transition at a much lower Re than that of the well-known Type I instability. This early transition is due to the excitation of the Type II. Presented are the neutral stability results concerning these instabilities by solving newly formulated stability equations with consideration of whole convective terms. When the present numerical results are compared with the previously known results, the value of critical Re corresponding to Type I is moved from ${Re}_{c.1}$=285.3 to 270.2 and the value corresponding to Type II from ${Re}_{c.2}$=69.4 to 36.9, respectively. Also, the corresponding wave number is moved fro)m $k_1$=0.378 to 0.386 for Type I; from $k_2$=0.279 to 0.385 for Type II. For Type II, the upped limit of wave number and azimuth angle is $k_u$=0.5872, $\varepsilon_u$=$-17.5^{\circ}$, while its lower limit is near $k_u$=0, $\varepsilon_u$=$-28.4^{\circ}$. This implies that the disturbances will be relatively fast amplified at small Re and within narrow bands of wave number compared with the previous results.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.75-79
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• 2008

Since tunnel construction order was placed one by one, various sensors and actuators installed at the RTU and higher level system in each tunnel maintenance office had their own protocols depending on construction company. The TGMS testbed established on the extended region of Yong-dong Highway, for example, did not have consistent protocol between each automation levels and management levels without considering the functions and/or roles of each level. The management sever in each tunnel was simply networked to the TGMS server. Therefore, it is impossible to implement a new control algorithm as well as to integrate each other since each tunnel was constructed by different company. So, if the construction company is out of business, there is no way to maintain the corresponding tunnel effectively. In order to solve this problem, all the necessary standard protocols was established between automation level and management levels. These interface standards provide the clear classification between individual tunnel system and tunnel management system. So, even if construction company is different, its effect is minimized, so that it is expected to successfully establish PC based TGMS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.743-744
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• 2008

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.9
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• pp.916-920
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• 2008

The personal workspace consists of user- specified computing environment such as user profile, applications and their configurations, and user data. Mobile computing devices (i.e., cellular phones, PDAs, laptop computers, and Ultra Mobile PC) are getting smaller and lighter to provide personal work-space ubiquitously. However, various personal work-space mobility solutions (c.f. VMWare Pocket ACE[1], Mojopac[2], u-PC[3], etc.) are appeared with the advance of virtualization technology and portable storage technology. The personal workspace can be loaded at public PC using above solutions. Especially, we proposed a framework called ubiquitous personal computing environment (u-PC) that supports mobility of personal workspace based on wireless iSCSI network storage in our previous work. However, previous u-PC could support limited applications, because it uses IRP (I/O Request Packet) forwarding technique at filter driver level on Windows operating system. In this paper, we implement OS-level virtualization technology using system call hooking on Windows operating system. It supports personal workspace mobility and covers previous u-PC limitation. Also, it overcomes personal workspace loading overhead that is limitation of other solutions (i.e., VMWare Pocket ACE, Mojopac, etc). We implement a prototype consisting of Windows XP-based host PC and Linux-based mobile device connected via WiNET protocol of UWB. We leverage several use~case models of our framework for proving its usability.

• Archives of design research
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• v.11 no.3
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• pp.177-185
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• 1998

Started from the Industrial Revolution in England, the design movement, the concept of plastic arts is spread and developed in many European countries. It meets new phase due to the much more developed industrial techniques and internationalized era since the World War II. The concept of identity in design appeared with industrial diversification, specialization, and inter- nationalization comes out through every visual identification standards. And the concept is used in public facilities and groups such as national institutions, schools, hospitals, or lots of religious bodies, as well as in industries to aim at the most profit from products' sale. Since the opening of Seoul National University of Technology in 1910, the university which has long history and tradition of about 90 years has used the unique visual identification in changing the University name to meet with the surrounding environment and the timely characteristics. However, the English name for the University was changed in 1998, so the new era to leap was open. Therefore, the University introduced formally the concept of U. I. (University Identification) with the new image. It is an inevitable outcome of modern time.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.493-501
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• 2001

B2C is not doing well in Asia and Pacific countries in comparison to U.S. and Europe. But there is misunderstanding of low growth of B2C electric commerce caused by cultural factor. Consumers in market are rational to decide their purchase according to total cost - market price and transaction cost. I examined this with data of Korea and U.S. Transaction cost in real market is less in Korea than in U.S. but that of electric commerce, it is much less in U.S. As a result, the choice of consumers in Korea is real market transaction while consumers in U.S. choose electric commerce.

• Journal of the Korea Computer Industry Society
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• v.2 no.6
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• pp.747-758
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• 2001

While developing the military intelligence systems, inter-operation problems which are even existed in the advanced countries must be secured. So we intend to contribute the development of concerned theories by suggesting the process and results of the operational architecture(OA) in C4ISR architecture framework that U.S. military researched and setup based on C4ISR architecture framework theory and BPR methodology.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.88.2-88.2
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• 2007

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.3-10
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• 2014

This study investigated whether Korean vowels, /ɨ/ and /u/, are distinctively perceived after a labial consonant given the fact that native and Sino-Korean nouns showed only vowel /u/ after a labial consonant while this pattern was massively broken by the recent introduction of loanwords. For this purpose, a perception experiment was conducted with $V_1C_1V_2$ sequences in which different vowels /a, i, u/ and consonants /p, t, k/ occurred in $V_1$ and $C_1$ before the target $V_2$, /ɨ/ and /u/. The data was produced by six speakers each from two different age groups, Age20 and Age40/50 in the read speech style. The results showed that consonant /p/ attracted significantly more responses of /u/ from /VCɨ/ sequences and significantly less responses of /u/ from /VCu/ sequence than the other consonants did in both age groups. Furthermore, Age20 group showed significantly less percentage of /u/ responses than Age40 group when the preceding consonant was /p/ regardless of the target vowel. We suggest therefore that unlike the traditional belief of labial assimilation, there is neutralization after a labial consonant in which vowels /ɨ/ and /u/ are often realized as any sound between two vowels, /ɨ/ and /u/. That is, this vowel change is not categorial but it rather produces an ambiguous stimulus which attracts different responses from different listeners. Ambiguous stimulus was produced due to coarticulatory efforts in speech production and perceptual compensation. We also argue that there is generational difference such that Age40/50 group speakers showed stronger tendency to produce /u/ after a labial consonant regardless of whether the target vowel was /ɨ/ or /u/.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.457-469
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• 2008

In this paper, we study the existence of positive solutions for the following nonlinear m-point boundary value problem with p-Laplacian: $\{{{{(\phi_p(u'))'\;+\;f(t,u(t))=0, \;0<t<1,} \atop u'(0)={\sum}{^{m-2}_{i=1}}\;a_iu'(\xi_i),} \atop u(1)={\sum}{^k_{i=1}}\;b_iu(\xi_i)\;-\;{\sum}{^s_{i=k+1}}\;b_iu(\xi_i)\;-\;{\sum}{^{m-2}_{i=s+1}}\;b_iu'(xi_i),}$ where ${\phi}_p(s)$ is p-Laplacian operator, i.e., ${\phi}_p(s)=\mid s\mid^{p-2}s$, p>1, ${\phi}_q\;=\;({\phi}_p)^{-1}$, $\frac{1}{p}+\frac{1}{q}=1$, $1\;{\leq}\;k\;{\leq}\;s\;{\leq}m\;-\;2$, $b_i\;{\in}\;(0,+{\infty})$ with $0\;<\;{\sum}{^k_{k=1}}\;b_i\;-\;{\sum}{^s_{i=k+1}}\;b_i\;<\;1$, $0\;<\;{\sum}{^{m-2}_{i=1}}\la_i\;<\;1$, $0\;<\;{\xi}_1\;<\;{\xi}_2\;<\;{\cdots}\;<\;{\xi}_{m-2}\;<\;1$, $f\;{\in}\;C([0,\;1]\;{\times}\;[0,\;+{\infty}),\;[0,\;+{\infty}))$. We show that there exists one or two positive solutions by using fixed-point theorem for operator on a cone. The conclusions in this paper essentially extend and improve the known results.