• Journal of the Korean Geotechnical Society
• /
• v.31 no.9
• /
• pp.53-68
• /
• 2015

Longitudinal strain is an important component of seismic design for buried pipelines. A design procedure which determines the wavelength from site natural period and shear wave velocity of the soil layer and closed-form solutions of pipelines under a harmonic motion is typically used in design. However, the applicability of the procedure has not yet been thoroughly investigated. In this paper, displacement-time histories extracted from 1D site response analyses are used in 3D shell-spring model to accurately predict the response of pipelines. The results are closely compared to those from the design procedure. The area of interest is East Siberia. Performing a site response analysis to determine site specific displacement time history is highlighted. The site natural period may be used to predict the predominant period of the acceleration time history, but cannot be used to estimate the predominant period of the displacement time history. If an accurate estimate of the predominant period of the displacement time history is provided, it is demonstrated that the design equation can be successfully used to predict the response of pipelines.

• Sleep Medicine and Psychophysiology
• /
• v.5 no.2
• /
• pp.119-133
• /
• 1998

Attentional processes facilitate cognitive and behavioral performance in several ways. Attention serves to reduce the amount of information to receive. Attention enables humans to direct themselves to appropriate aspects of external environmental events and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Attention is not a unitary process that can be localized to a single neuroanatomical region. Before the cortical registration of sensory information, activation of important subcortical structures occurs, which is called as an orienting response. Once sensory information reaches the sensory cortex, a large number of perceptual processes occur, which provide various levels of perceptual resolution of the critical features of the stimuli. After this preattentional processing, information is integrated within higher cortical(heteromodal) systems in inferior parietal and temporal lobes. At this stage, the processing characteristics can be modified, and the biases of the system have a direct impact on attentional selection. Information flow has been traced through sensory analysis to a processing stage that enables the new information to be focused and modified in relation to preexisting biases. The limbic and paralimbic system play significant roles in modulating attentional response. It is labeled with affective salience and is integrated according to ongoing pressures from the motivational drive system of the hypothalamus. The salience of information greatly influences the allocation of attention. The frontal lobe operate response selection system with a reciprocal interaction with both the attention system of the parietal lobe and the limbic system. In this attentional process, the search with the spatial field is organized and a sequence of attentional responses is generated. Affective, motivational and appectitive impulses from limbic system and hypothalamus trigger response intention, preparation, planning, initiation and control of frontal lobe on this process. The reticular system, which produces ascending activation, catalyzes the overall system and increases attentional capacity. Also additional energetic pressures are created by the hypothalamus. As psychophysiological measurement, skin conductance, pupil diameter, muscle tension, heart rate, alpha wave of EEG can be used. Event related potentials also provide physiological evidence of attention during information process. NI component appears to be an electrophysiological index of selective attention. P3 response is developed during the attention related to stimulus discrimination, evaluation and response.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.12A
• /
• pp.1225-1232
• /
• 2008

In this paper, we describe a compensation method of diurnal effect which is one of the factors giving large effect on the performance when using ground-wave signals like Loran-C for a backup and substitute navigation system of global satellite navigation system such as GPS, and currently many researches of the topics are doing in USA and in Europe. In order to compensate diurnal effect, we find periodic frequency components by using the Least Square Spectral Analysis (LSSA) method at first and then compensate the effect by subtracting the estimated compensation signal, obtained by using the estimated amplitude and phase of the individual frequency component, from the original signal. In this paper, we propose a simple compensation algorithm and analysis the performance through simulations. From the results, it is observed that the amplitude and phase can be estimated with under 5 % and 0.17 % in a somewhat poor receiving situation with 0 dB Signal to Noise Ratio (SNR). Also, we analyze the obtainable performance improvement after compensation by using the measured Loran-C data. From the results, it is observed that we can get about 22 % performance improvement when a moving average with 5 minutes interval is employed.

• Journal of Intelligence and Information Systems
• /
• v.16 no.4
• /
• pp.173-193
• /
• 2010

The World Wide Web is transitioning from being a mere collection of documents that contain useful information toward providing a collection of services that perform useful tasks. The emerging Web service technology has been envisioned as the next technological wave and is expected to play an important role in this recent transformation of the Web. By providing interoperable interface standards for application-to-application communication, Web services can be combined with component-based software development to promote application interaction and integration within and across enterprises. To make Web services for service-oriented computing operational, it is important that Web services repositories not only be well-structured but also provide efficient tools for an environment supporting reusable software components for both service providers and consumers. As the potential of Web services for service-oriented computing is becoming widely recognized, the demand for an integrated framework that facilitates service discovery and publishing is concomitantly growing. In our research, we propose a framework that facilitates Web service discovery and publishing by combining clustering techniques and leveraging the semantics of the XML-based service specification in WSDL files. We believe that this is one of the first attempts at applying unsupervised artificial neural network-based machine-learning techniques in the Web service domain. We have developed a Web service discovery tool based on the proposed approach using an unsupervised artificial neural network and empirically evaluated the proposed approach and tool using real Web service descriptions drawn from operational Web services repositories. We believe that both service providers and consumers in a service-oriented computing environment can benefit from our Web service discovery approach.

• Journal of Navigation and Port Research
• /
• v.40 no.1
• /
• pp.15-20
• /
• 2016

In this study we measured a differential ASF to improve the accuracy of time synchronization with the signal transmitted from Pohang 9930M Loran station. We obtained the differential ASF which is calculated from a difference of the TOA measurements between KRISS and Chungnam National University(CNU), and KRISS and National Maritime PNT Office respectively. The TOA measurement at KRISS was measured by UTC(KRIS) reference clock and other sites were measured by atomic clocks respectively. The time variations of differential ASF measurements at CNU and National Maritime PNT Office were within $0.1{\mu}s$ and $0.05{\mu}s$ respectively. And we found the time variations of $0.1{\mu}s$ depending on the surrounding radio-wave environments from the differential ASF measurements of 60 minute moving averages. We can improve the accuracy of time synchronization of the local clock to within 10 ns by compensating the differential ASF through removing the common component of ASF. And we measured the absolute ASF between the Pohang transmit station and KRISS by the measurement technique of absolute time delay using a cesium atomic clock. The average ASF between two points is about $3.5{\mu}s$.

• Korean Journal of Optics and Photonics
• /
• v.16 no.4
• /
• pp.326-333
• /
• 2005

Phase-only encryption scheme using exclusive-OR rules in Fourier plane and a single path decryption system are presented. A zero-padded original image, multiplied by a random phase image, is Fourier transformed and its real-valued data is encrypted with key data by using XOR rules. A decryption is simply performed based on 2-1 setup with spatial filter by Fourier transform for multiplying phase-only encrypted data by phase-only key data, which are obtained by phase-encoding process, and spatial filtering for zero-order elimination in inverse-Fourier plane. Since the encryption process is peformed in Fourier plane, proposed encryption scheme is more tolerant to loss of key information by scratching or cutting than previous XOR encryption method in space domain. Compare with previous phase-visualization systems, due to the simple architecture without a reference wave, our system is basically robust to mechanical vibrations and fluctuations. Numerical simulations have confirmed the proposed technique as high-level encryption and simple decryption architecture.

• Food Science and Preservation
• /
• v.14 no.6
• /
• pp.722-726
• /
• 2007

Extracting and analytical conditions of curcumin, and removal of bitterness substance from Curcuma longa L. were investigated. Absorption maxima was shown to be 424 nm at methanol solvent. Optimal conditions for analysis of curcumin was Zorbax eclipse $C_{18}$ column ; mobile phase, 75% MeOH ; flow rate, 0.8 mL/min ; wave length, UV 424 nm. Curcumin component was analyzed to be the highest content in methanol extract. In all samples, extraction yield by heating was shown to be effective as compared to room temperature. Curcumin contents of methanol and ethanol extracts in extraction of room temperature were 14.4 and 14.2 times higher than that of water extract, respectively. Two hot solvent extracts has a high curcumin content being 150 mg% as compared to room temperature. Extracting time was an effective condition when it was extracted for 60 minutes for elevating the curcumin content of water and methanol extracts. Bitter substance (BS) was markedly decreased in water extract by heat treatment of above $80^{\circ}C$. BS was weak in $121^{\circ}C$ treatment than in room temperature and it was however strong in $100^{\circ}C$ treatment. RT and $70^{\circ}C$ heat treatment were not different in BS intensity.

• Journal of Korea Water Resources Association
• /
• v.45 no.1
• /
• pp.39-52
• /
• 2012

Surface-subsurface interactions are an intrinsic component of the hydrologic response within a watershed. In general, these interactions are considered to be one of the most difficult areas of the discipline, particularly for the modeler who intends simulate the dynamic relations between these two major domains of the hydrological cycle. In essence, one major complexity is the spatial and temporal variations in the dynamically interacting system behavior. The proper simulation of these variations requires the need for providing an appropriate coupling mechanism between the surface and subsurface components of the system. In this study, an approach for modelling surface-subsurface flow and transport in a fully intergrated way is presented. The model uses the 2-dimensional diffusion wave equation for sheet surface water flow, and the Boussinesq equation with the Darcy's law and Dupuit-Forchheimer's assumption for variably saturated subsurface water flow. The coupled system of equations governing surface and subsurface flows is discretized using the finite volume method with central differencing in space and the Crank-Nicolson method in time. The interactions between surface and subsurface flows are considered mass balance based on the continuity conditions of pressure head and exchange flux. The major module consists of four sub-module (SUBFA, SFA, IA and NS module) is developed.

• Journal of Intelligence and Information Systems
• /
• v.16 no.2
• /
• pp.33-54
• /
• 2010

The World Wide Web is transitioning from being a mere collection of documents that contain useful information toward providing a collection of services that perform useful tasks. The emerging Web service technology has been envisioned as the next technological wave and is expected to play an important role in this recent transformation of the Web. By providing interoperable interface standards for application-to-application communication, Web services can be combined with component based software development to promote application interaction both within and across enterprises. To make Web services for service-oriented computing operational, it is important that Web service repositories not only be well-structured but also provide efficient tools for developers to find reusable Web service components that meet their needs. As the potential of Web services for service-oriented computing is being widely recognized, the demand for effective Web service discovery mechanisms is concomitantly growing. A number of public Web service repositories have been proposed, but the Web service taxonomy generation has not been satisfactorily addressed. Unfortunately, most existing Web service taxonomies are either too rudimentary to be useful or too hard to be maintained. In this paper, we propose a Web service taxonomy generation framework that combines an artificial neural network based clustering techniques with descriptive label generating and leverages the semantics of the XML-based service specification in WSDL documents. We believe that this is one of the first attempts at applying data mining techniques in the Web service discovery domain. We have developed a prototype system based on the proposed framework using an unsupervised artificial neural network and empirically evaluated the proposed approach and tool using real Web service descriptions drawn from operational Web service repositories. We report on some preliminary results demonstrating the efficacy of the proposed approach.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.33 no.3
• /
• pp.122-130
• /
• 2021

A wind-speed estimation at the arbitrary elevations is key component for the design of the offshore wind energy structures and the computation of the wind-wave generation. However, the wind-speed estimation of the target elevation has been carried out by using the typical functions and their typical parameters, e.g., power and logarithmic functions because the available wind speed data is limited to the specific elevation, such as 2~3m, 10 m, and so on. In this study, the parameters of the vertical profile functions are estimated with optimal and analyzed the parameter ranges using the HeMOSU-1 platform wind data monitored at the eight different locations. The results show that the mean value of the exponent of the power function is 0.1, which is significantly lower than the typically recommended value, 0.14. The values of the exponent, the friction velocity, and the roughness parameters are in the ranges 0.0~0.3, 0~10 (m/s), and 0.0~1.0 (m), respectively. The parameter ranges differ from the typical ranges because the atmospheric stability condition is assumed as the neutral condition. To improve the estimation accuracy, the atmospheric condition should be considered, and a more general (non-linear) vertical profile functions should be introduced to fit the diverse profile patterns and parameters.