• 건축역사연구
• /
• 제26권6호
• /
• pp.29-40
• /
• 2017

Soswaewon as a typical villa garden of Korea is a symbolic garden that its diverse compositions imply a specific meaning. This study reviewed the purpose of introduction, meaning, and location of the landscape plants as one of the compositions and covering quite a large part of Soswaewon through 48 Yeong (meaning 48 poems of Soswaewon) and Soswaewondo (meaning Map of Soswaewon). In 48 Yeong, 27 verses describe landscape plants as their key poetic matters. The most frequently mentioned top 3 plants are bamboos, pine trees, and Japanese apricots. The three plants are called Sehansamwoo(歲寒三友) showing constant fidelity and loyalty in any changing situations, which was regarded to represent the nature of scholars. And also the study examined the frequency and planting location of the plants in Soswaewon by comparing 48 Yeong and Soswaewondo, and the result showed some differences between them. That seems to be caused by the limitations in the comparison, because in case of 48 Yeong, the location and frequency of landscape plants can be examined only through the context of the verses, and Soswaewondo showed different production time from 48 Yeong and expressed them only in a form of drawing. The plants have symbolic meanings multi-layered and ambiguous. With their symbolic meanings, the landscape plants reviewed through 48 Yeong consistently represent fidelity and loyalty, man of virtue, and hermit. That is, Soswaewon is the garden granting some significance to its compositions by interacting with the things.

• 한국전기전자재료학회논문지
• /
• 제29권10호
• /
• pp.625-629
• /
• 2016

Electrical and optical properties of the AC voltage driven organic light-emitting diodes were investigated by measuring the electroluminescence of the device. Device structure of ITO(170 nm)/TPD(40 nm)/Alq3(60 nm)/LiF(0.5 nm)/Al(100 nm) was manufactured using a thermal evaporation. Sinusoidal and square-type AC voltage was applied to the device using a function generator. Amplitude of the applied voltage was 9.0 V, and a frequency was varied from 50 Hz to 50 kHz. Electroluminescence out of the device was measured in a Si photodetector simultaneously with the applied voltage together. An intensity and a delayed residual luminescence from the device were depended on the frequency of the sinusoidal voltage. It is thought to be due to a contribution of the capacitive nature in the equivalent circuit of the device. An electron mobility was estimated using a time constant obtained from the luminescence of the device driven by the square-type AC voltage.

• Journal of Electrical Engineering and Technology
• /
• 제10권3호
• /
• pp.1093-1101
• /
• 2015

Partial Discharge (PD) is a physical phenomenon, which causes defects and damages to the insulation. This phenomenon is regarded as the most important source of fault and defect in power transformers. Therefore, methods of high speed and precision are considered of special importance for the maintenance of transformers in localization of the origin of partial discharge. In this paper, the transformer winding is first modeled in a transient state by using RLC ladder network and multiconductor transmission line (MTL) models. The parameters of the two models were calculated by Ansoft Maxwell software, and the simulations were performed by Matlab software. Then, the PD pulses were applied to the models with different widths of pulses. With regard to the fact that the signals received after the application of PD had a variable frequency nature over time, and based on the wavelet transform and signal energy, a new method was presented for the localization of PD. Ultimately; the mentioned method was implemented on a 20 kV winding distribution transformer. Then, the performances of the models used in this paper, including RLC and MTL models, were compared in different frequency bands for the correct distinction of partial discharge location.

• Journal of applied mathematics & informatics
• /
• 제35권3_4호
• /
• pp.241-260
• /
• 2017

An analysis is made to study the solute transport in a Casson fluid flow through an annulus in presence of oscillatory flow field and determine how this flow influence the solute dispersion along the annular region. Axial dispersion coefficient and the mean concentration expressions are calculated using the generalized dispersion model. Dispersion coefficient in oscillatory flow is found to be a function of frequency parameter, Schmidt number, and the pressure fluctuation component besides its dependency on yield stress of the fluid, annular gap and time in the case of steady flow. Due to the oscillatory nature of the flow, the dispersion coefficient changes cyclically and the amplitude and magnitude of the dispersion increases initially with time and reaches a non - transient state after a certain critical time. This critical value varies with frequency parameter and independent of the other parameters. It is found that the presence of inner cylinder and increase in the size of the inner cylinder inhibits the dispersion process. This model may be used in understanding the dispersion phenomenon in cardiovascular flows and in particular in catheterized arteries.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.402-403
• /
• 2014

Damping of multi-span tube with loose supports according to the finite support clearances is investigated through the experimental modal analysis. Loose intermediate support leads to strong nonlinearity in tube dynamics, provides statistical nature, and increases tube damping through impacting and friction at the supports. Fraction of critical damping was estimated by the modal curve fitting to parameter estimation from the measured frequency response functions. Magnitude of random excitation force, which can reproduce the in-situ excitation in operating environment, was maintained as constant value with a fine tolerance during vibration testing. Range of input force was carefully selected to cover from the low magnitude excitation for linearly behaved tube motion to high magnitude of force for nonlinearly-behaved tube motion. Estimated critical damping ratio shows scatters in data and tends to increase as the magnitude of rising force and decrease with upward frequency variation. Larger size of support gap increases multi-span tube damping for high magnitude of excitation.

• 한국경영과학회지
• /
• 제40권4호
• /
• pp.49-63
• /
• 2015

Keyword indexed in multidisciplinary journals show trends about science and technology innovation. Nature and Science were selected as multidisciplinary journals for our analysis. In order to reduce the effect of plurality of keyword, stemming algorithm were implemented. After this process, we fitted growth curve of keyword (stem) following bass model, which is a well-known model in diffusion process. Bass model is useful for expressing growth pattern by assuming innovative and imitative activities in innovation spreading. In addition, we construct keyword co-occurrence network and calculate network measures such as centrality indices and local clustering coefficient. Based on network metrics and yearly frequency of keyword, time series analysis was conducted for obtaining statistical causality between these measures. For some cases, local clustering coefficient seems to Granger-cause yearly frequency of keyword. We expect that local clustering coefficient could be a supportive indicator of emerging science and technology.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.77-81
• /
• 2003

SDM (Structural Dynamics Modification) is a tool to improve dynamic characteristics of a structure, more specifically of a base structure, by adding or deleting auxiliary (modifying) structures. In this paper, the goal of the optimal SDM is set to maximize the natural frequency of a base plate structure by attaching serially-connected beam stiffeners. The design variables are chosen as positions of the attaching beam stiffeners, where the number of stiffeners is considered as a design space. The problem of non-matching interface nodes between the base plate and beam stiffeners is solved by using localized Lagrange multipliers, which act to glue the two structures with non-matching interface nodes. As fer the cases of non-matching interface nodes problem, the governing equation of motion of a structure can be considered from the viewpoint of a topological modification, which involves the change of the number of structural members and DOFs. Consequently, the eigenpairs of the beam-stiffened plate structure are obtained by using an eigen reanalysis technique of topological modifications. Evolution Strategies (ES), which is a probabilistic population-based optimization technique that mimics the principles from biological evolution in nature, is utilized as a mean for the optimization.

• 혜화의학회지
• /
• 제9권1호
• /
• pp.691-710
• /
• 2000

We came to the conclusion after considering all the information from many kinds of book on herb medicine which is treatment method of "quickening blood and transforming stasis" for external wound. 1. Angelicae sinensis Radix and Angelicae Gigantis Radix are account for 16%(57times) of monarch drug and ministerial drug in all. It means that effect of "quickening blood and transforming stasis" of Angelicae sinensis Radix and Angelicae Gigantis Radix are more excellent than any other herb medicine. 2. In the case of the monarch drug, Angelicae sinensis Radix and Rhizoma Rhei are used at most, treatment method is divided into "expel stasis" and "quickening blood and transforming stasis". 3. In the case of the monarch drug, there are Dolomitum, Eupolyphaga, Dracinis Resina, Crinis Carbonisatus, Acronychiae Ligum, Pini Ramulus etc which have strong treatment effect and pecunliar sort. 4. In the case of the ministerial drug, there are Dracinis Resina, Brassica Rapa, Pyritunm, Liquidambaris Resina etc which are unusual sort. 5. In the order of frequency in use of monarch drug and ministerial drug in nature, it is hot, mean, cold drug. In the order of frequency in use of monarch drug and ministerial drug in flavors, it is sharp, pungent, sweat.

• ETRI Journal
• /
• 제35권4호
• /
• pp.687-696
• /
• 2013

The development of proxy caching is essential in the area of video-on-demand (VoD) to meet users' expectations. VoD requires high bandwidth and creates high traffic due to the nature of media. Many researchers have developed proxy caching models to reduce bandwidth consumption and traffic. Proxy caching keeps part of a media object to meet the viewing expectations of users without delay and provides interactive playback. If the caching is done continuously, the entire cache space will be exhausted at one stage. Hence, the proxy server must apply cache replacement policies to replace existing objects and allocate the cache space for the incoming objects. Researchers have developed many cache replacement policies by considering several parameters, such as recency, access frequency, cost of retrieval, and size of the object. In this paper, the Weighted-Rank Cache replacement Policy (WRCP) is proposed. This policy uses such parameters as access frequency, aging, and mean access gap ratio and such functions as size and cost of retrieval. The WRCP applies our previously developed proxy caching model, Hot-Point Proxy, at four levels of replacement, depending on the cache requirement. Simulation results show that the WRCP outperforms our earlier model, the Dual Cache Replacement Policy.

• 한국재료학회지
• /
• 제21권7호
• /
• pp.377-383
• /
• 2011

Thermoelectric power, dc conductivity, and the dielectric relaxation properties of $La_2NiO_{4.03}$ are reported in the temperature range of 77 K - 300 K and in a frequency range of 20 Hz - 1 MHz. Thermoelectric power was positive below 300K. The measured thermoelectric power of $La_2NiO_{4.03}$ decreased linearly with temperature. The dc conductivity showed a temperature variation consistent with the variable range hopping mechanism at low temperatures and the adiabatic polaron hopping mechanism at high temperatures. The low temperature dc conductivity mechanism in $La_2NiO_{4.03}$ was analyzed using Mott's approach. The temperature dependence of thermoelectric power and dc conductivity suggests that the charge carriers responsible for conduction are strongly localized. The relaxation mechanism has been discussed in the frame of the electric modulus and loss spectra. The scaling behavior of the modulus and loss tangent suggests that the relaxation describes the same mechanism at various temperatures. The logarithmic angular frequency dependence of the loss peak is found to obey the Arrhenius law with activation energy of ~ 0.106eV. At low temperature, variable range hopping and large dielectric relaxation behavior for $La_2NiO_{4.03}$ are consistent with the polaronic nature of the charge carriers.