• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.1
• /
• pp.9-15
• /
• 2010

This paper analyzed the problems of the Korean output regulation in the relevant band through an analytic comparison of the current trend of each country and their standard values concerning electric field strength (technical standard) of weak wireless stations with less than 135kHz. In connection with the standard value of electric field strength of each country, which has been proposed in the registration of the appropriate electric wave, the paper aims to propose the standard value of electric field strength that could actually be introduced for suitable unauthorized wireless devices (weak wireless devices) in Korea. Provided that the Korean standard may be upgraded based on the tolerances of electric field strength proposed m this paper, this is expected to be committed to the distribution and advancement of weak wireless devices; and further it is anticipated to be prepared with competitiveness not only in the Korean communications market, but also in the international communications market.

• Journal of the Korean Mathematical Society
• /
• v.54 no.5
• /
• pp.1483-1504
• /
• 2017

We consider weak solutions of the instationary Navier-Stokes system in a smooth bounded domain ${\Omega}{\subset}{\mathbb{R}}^3$ with initial value $u_0{\in}L^2_{\sigma}({\Omega})$. It is known that a weak solution is a local strong solution in the sense of Serrin if $u_0$ satisfies the optimal initial value condition $u_0{\in}B^{-1+3/q}_{q,s_q}$ with Serrin exponents $s_q$ > 2, q > 3 such that ${\frac{2}{s_q}}+{\frac{3}{q}}=1$. This result has recently been generalized by the authors to weighted Serrin conditions such that u is contained in the weighted Serrin class ${{\int}_0^T}({\tau}^{\alpha}{\parallel}u({\tau}){\parallel}_q)^s$ $d{\tau}$ < ${\infty}$ with ${\frac{2}{s}}+{\frac{3}{q}}=1-2{\alpha}$, 0 < ${\alpha}$ < ${\frac{1}{2}}$. This regularity is guaranteed if and only if $u_0$ is contained in the Besov space $B^{-1+3/q}_{q,s}$. In this article we consider the limit case of initial values in the Besov space $B^{-1+3/q}_{q,{\infty}}$ and in its subspace ${{\circ}\atop{B}}^{-1+3/q}_{q,{\infty}}$ based on the continuous interpolation functor. Special emphasis is put on questions of uniqueness within the class of weak solutions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.455-458
• /
• 2004

This study uses time series analyses to evaluate fluctuation of water levels in a geothermal water well due to pumping, in relation to rainfall at Dongrae hot-spring site on the southeastern coast of tile Korean peninsula. The volume of water pumped from the public study wells ranges from 542 to 993 m$^3$/month, and the minimum water level ranged from 35 to 144.7 m during the measured period. Autocorrelation analysis was conducted for the withdrawal rate at the public wells, water levels and rainfall. The autocorrelation of the withdrawal rate shows distinct periodicity with 3 months of lag time, the autocorrelation of rainfall shows weak linearity and short memory with 1 months of lag time, and the autocorrelation of water levels shows weak linearity and short memory with 2 months of lag time. The cross-correlation between the pumping volume and the minimum water level shows a maximum value 1 at a delayed time of 34 months. The cross-correlation between rainfall and the minimum water level shows a maximum value of 0.39 at a delayed time of 32 months.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.3
• /
• pp.378-385
• /
• 2012

This study carried out to investigate the effects of yacon powder on yellow layer cake made with weak flour. After making yellow layer cake with yacon powder, water activity, crumb texture, crumb color, and sensory characteristics were investigated. After 1 day of storage, Aw value of control cake with weak flour did not show any significant differences, whereas those with 2, 4, and 6% yacon powder showed a significant increase in Aw. During storage, the Aw values of yellow layer cakes containing yacon powder decreased. Hardness and gumminess of yellow layer cakes containing yacon powder decreased compared to those of control, whereas springiness and cohesiveness of yellow layer cakes increased compared to those of control. Hardness, springiness, cohesiveness, and gumminess all increased with storage time. Further a higher percentage of yacon powder was associated with lower L and b values as well as a higher a value. The micrographs of yellow layer cakes with yacon powder showed slightly coarser porosity than that of control. The results of the sensory test showed that the overall acceptability of 2% yacon powder cake was the highest.

• Smart Structures and Systems
• /
• v.17 no.3
• /
• pp.413-429
• /
• 2016

The recent research on proper orthogonal decomposition (POD) has revealed the linkage between proper orthogonal modes and linear normal modes. This paper presents an investigation into the modal identifiability of an instrumented cable-stayed bridge using an adapted POD technique with a band-pass filtering scheme. The band-pass POD method is applied to the datasets available for this benchmark study, aiming to identify the vibration modes of the bridge and find out the so-called deficient modes which are unidentifiable under normal excitation conditions. It turns out that the second mode of the bridge cannot be stably identified under weak wind conditions and is therefore regarded as a deficient mode. To judge if the deficient mode is due to its low contribution to the structural response under weak wind conditions, modal coordinates are derived for different modes by the band-pass POD technique and an energy participation factor is defined to evaluate the energy participation of each vibration mode under different wind excitation conditions. From the non-blind datasets, it is found that the vibration modes can be reliably identified only when the energy participation factor exceeds a certain threshold value. With the identified threshold value, modal identifiability in use of the blind datasets from the same structure is examined.

• YAKHAK HOEJI
• /
• v.32 no.5
• /
• pp.313-318
• /
• 1988

Radioprotective ginseng protein fraction was isolated from Korean white ginseng and its cytotoxic effect on CHO-K1 cells was studied by the method of measuring the relative cell survival and total cellular protein content (FRAME method). When ginseng protein at the dose of 300, 600, 900, $1200{\mu}g/ml$ was treated to cells for 24 hrs, the relative survival was significantly decreased at the concentration of above $600{\mu}g/ml$, indicating the presence of cytotoxic effect of the protein at certain concentration. When cellular protein content was measured after ginseng protein at the dose of 300, 600, 900, $1200\;{\mu}g/ml$ was treated, the amount of cellular protein was significantly reduced at the concentration above $600{\mu}g/ml$ in the case of 24 hr treatment and at all concentrations including $300{\mu}g/ml$ in the case of 72 hr treatment. The data suggest that the protein may inhibit cell growth, resulting in the reduction of live cells in culture. $ID_{50}$ value which is the concentration of ginseng protein that reduces the total cellular protein content to 50% of the control was calculated as 2276.86 and $1323.32\;{\mu}g/ml$ in groups treated for 24 and 72 hr, respectively. Since $ID_{50}$ value of above $1000{\mu}g/ml$ indicates very weak cytotoxicity, the ginseng protein seems to exert very weak cytotoxic effect on CHO-K1 cells.

• Bulletin of the Korean Mathematical Society
• /
• v.57 no.4
• /
• pp.1003-1031
• /
• 2020

We consider the following Dirichlet initial boundary value problem with a gradient absorption and a nonlocal source $$\frac{{\partial}u}{{\partial}t}-div({\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)={\lambda}u^k{\displaystyle\smashmargin{2}{\int\nolimits_{\Omega}}}u^sdx-{\mu}u^l{\mid}{\nabla}u{\mid}^q$$ in a bounded domain Ω ⊂ ℝ^N, where p > 1, the parameters k, s, l, q, λ > 0 and µ ≥ 0. Firstly, we establish local existence for weak solutions; the aim of this part is to prove a crucial priori estimate on |∇u|. Then, we give appropriate conditions in order to have existence and uniqueness or nonexistence of a global solution in time. Finally, depending on the choices of the initial data, ranges of the coefficients and exponents and measure of the domain, we show that the non-negative global weak solution, when it exists, must extinct after a finite time.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.16 no.4
• /
• pp.3611-3616
• /
• 1974

Alluvial plain of the coast of Kum river tail were found as being mostly consisted of weak foundation. The settlement of the ground, density and change of moisture content which were formed by the load due the construction of earth works were disclossed by the field investigations and laboratory tests. The results are as follow, 1) Banking materials are SM and soft soil stratum is CL. 2) Field moisture content; Wf=19-1.37c c; percentage of clay (less than 0.005mm) 3) optimum water content and maximum density of banking materials; rt=2.15$\mid$0.0165W(12%24%) 4) Density and moisture coutent of banking materials; rt=2.146-0.0095W (8%50%) 5) Density and moisture content of weak foundation; rt=2.06-0. 007W After construction (20%50%) Befor construction (40%60%) 6) Load and settlement of weak foundation; Everage settlement ratio; 12% of actual load p Maximum settlement ratio; 19% of actual load p Minimum settlement ratio: 5% of actual load p 7) Relation of cohesion and unconfined compression test value; c=1/2qu (qu<0.5kg/$\textrm{cm}^2$) c=1/3qu (qu<0.5kg/$\textrm{cm}^2$)

• Journal of International Academy of Physical Therapy Research
• /
• v.12 no.1
• /
• pp.2286-2294
• /
• 2021

Background: Exercise is necessary for the health of companion dogs. It is necessary to determine the relationship between height, weight, age and amount of exercise for the purpose of companion dog's health. Objectives: A survey was conducted in this study to small-dog owners living in Yongin city, Gyeonggi-do about their canine healthcare awareness. Design: Questionnaire design. Methods: The questionnaire was composed of exercise amount, type of exercise, and the necessity of exercise, general health condition, and environment. A total of 139 survey results were obtained. The average value of each item was analyzed and expressed in terms of frequency and percentage. Then, Pearson's correlation coefficients were used to find the relationship between these items. Results: The weight and height were not shown to have a significant difference in the amount of exercise in the results. The weight had a weak positive correlation with "exercise time of canine per day". The age had a weak negative correlation with "the number of canine exercise per week" and "frequency of canine exercise per day", while it had a weak positive correlation with "self-assessment of canine lack of exercise". Conclusion: Based on this study, it is believed that in the future, various environments where dogs can exercise are believed to be necessary for the era of convergence.

• Journal of the Korean Society of Food Culture
• /
• v.20 no.3
• /
• pp.352-359
• /
• 2005

The red ginseng powder was added to Yackwa dough as ratio to 0%, 2%, 4%, 6% and 8%, respectively to know effect of red ginseng powder on Yackwa quality and preservation. The expansion, color, texture and preference characters were investigated at 0,2 and 4 weeks, respectively. The peroxide and acid value were also measured. The 4% addition increased greatly expansion rate. In color test, L value lowed at addition of red ginseng powder and at long storage period. the b value lowed as the addition was increased, but a value was not affected by the addition of red ginseng powder. In mechanical texture test, addition of red ginseng powder had a tendency to show low cohessivness, springness, gumminess while hardness increased. The springness, brittleness and cohessivness decreased while hardness increased at long storage period. In sensory test, surface color, bitterness and red ginseng flavor were recognized strong by addition of red ginseng powder but oily taste, crispness, softness and overall preference were weak. The surface color and red ginseng flavor were strong at long storage period but sweetness, softness and overall preference decreased, respectively. The peroxide value increased at long storage period and decreased after 6 week. The 2% and 4% addition showed lower peroxide value compared to other treatment. The acid value increased at early storage period, but did not change after 4 weeks.