• Korean Journal of Social Welfare Studies
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• no.36
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• pp.253-280
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• 2008

Previous research indicates that depressive symptoms and alcohol consumption are highly correlated with each other. However, there is lack of consensus on the causal relationship between depressive symptoms and alcohol use. In order to address this limitation, this paper examines causal relationship between the two variables using non-recursive structural equation modeling, controlling sociodemographic and psycho-socio-behavioral variables. Data included 14,469 community dwelling individuals who participated in Korea Welfare Panel Study in 2006. Results showed that the effects of alcohol consumption on depressive symptoms was statistically significant, whereas the effects of depressive symptoms on alcohol consumption was not. Significant portions of the effects of psycho-socio-behavioral variables on depressive symptoms were indirect through their effects on alcohol consumption. Based on the results, implications for intervention and future research were discussed.

• The Journal of the Acoustical Society of Korea
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• v.29 no.4
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• pp.243-250
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• 2010

This paper proposes a spectral modeling of Korean traditional instrument, Haegeum, using cepstral analysis to naturally describe Haegeum sounds varying with time. To get a precise result of cepstral analysis, we set the frame size to 3 periods of input signal and more cepstral coefficients are used to extract formants. The performance is enhanced by flexibly controlling the cutoff frequency of bandpass filter depending on the resonances in the synthesis process of sinusoidal components and the deleting peaks remained in the residual signal. To detect the change of pitch, we divide the input frames into silence, attack, and sustain region and determine which region the current frame is involved in. Then, the proposed method readjusts the frame size according to the fundamental frequency in the case of the current frame is in attack region and corrects the extraction errors of the fundamental frequency for the frames in sustain region. With these processes, the synthesized sounds are much more similar to the originals. The evaluation result through the listening test by a Haegeum player says that the synthesized sounds are almost similar to originals (96~100 % similar to the original sounds).

• The Journal of Society for e-Business Studies
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• v.11 no.3
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• pp.73-88
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• 2006

As a computerized application for controlling enterprise processes, BPM(Business Process Management) has been received such concerns that many solution vendors developed their own process definition and storage methods. The fact causes the needs of process modeling standards for process model exchange and at the same time, requires the appropriate methodology for adopting the global standards. In this paper, we propose a transformation methodology of BPMN-based file into XMI(XML Metadata Interchange)-based neutral file format. We devised translation templates for 21 workflow patterns, and compared the results with BPEL4WS(Business Process Execution Language for Web Services) translation. As a result, our XMI transformation model enables more complete translation of process model in comparison with existing model, and thus can be practically utilized to the BPM vendors adopting BPMN standards.

• Earthquakes and Structures
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• v.3 no.6
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• pp.853-867
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• 2012

In this paper, a new type of passive energy dissipating system similar to added damping and stiffness (ADAS) and triangular added damping and stiffness (TADAS) is proposed and implemented in the analytical model of a building with hybrid structural system in the structure's base which we call it; Telescopic column. The behavior and performance of a high rise R.C. structure equipped with this system is investigated and compared with conventional base isolation systems such as rubber isolator bearings and friction pendulum bearings. For this purpose a series of ground acceleration records of the San Fernando, Long Beach and Imperial Valley earthquakes are used as the disturbing ground motions in a series of numerical simulations. The nonlinear numerical modeling which includes both material and geometric nonlinearities were carried out by using SAP2000 program. Results show suitable behavior of structures equipped with telescopic columns in controlling the upper stories drifts and accelerations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.161-165
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• 2003

In this paper, we investigate the issues on the design and implementation of tele-operation system based on the haptic interface. Here, the 3-DOF haptic device and the X-Y-Z stage are employed as master controller and slave system respectively. For this master-slave system, the force feedback algorithm, the modeling of virtual environments and the control method of X-Y-Z stage are presented. In this paper, internet network is used for data communication between master and slave. We construct virtual environment of the real convex surface from the force-feedback in controlling the X-Y-Z stage and measuring the force applied by the 3-DOF haptic device.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.143-149
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• 2010

Bandwidth and Buffer are critical network resources to determine the end-to-end quality of service. In this paper, we investigate several techniques on bandwidth and buffer management and classify them according to the types they used for controlling the throughput of a TCP/IP network. Moreover, in this paper, it present a new approach for modeling the active bandwidth and buffer control mechanisms for TCP/IP networks.

• Physical Therapy Korea
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• v.10 no.1
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• pp.97-108
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• 2003

Slipping during various kinds of movement often leads to potentially dangerous incidents of falling. The purpose of this paper was to review some of the research performed in the field including such topics as rating scales for balance, kinematics and kinetics of slipping, adaptation to slippery conditions, postural and balance control, and protective movement during falling. Controlling slipping and fall injuries requires a multifaceted approach. Environmental conditions (state of floor surface, tidiness, lighting, etc), work task (walking, carrying, pushing, lifting, etc), and human behavior (anticipation of hazards, adaptation to risks, risk taking, etc) must be accounted for in the assessment of slip and fall-related risks. Future directions of research must deal with modeling of basic tribophysical, biomechanical, and postural control process involved in slipping and falling.

• Journal of the Korean Society of Visualization
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• v.2 no.1
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• pp.12-17
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• 2004

The physical characteristics of soot near the soot inception point were investigated with various measurements. In-situ measurements of particle size and volume fraction were introduced based on time resolved laser-induced incandescence (TIRE-LII) and laser-induced ion mobility (LIIM). The one has more convenience and accuracy than conventional LII technique and the other works best for particle sizes of a few nanometers at high concentrations in a uniform concentration field. A complementary ex-situ measurement of particle size is nano differential mobility analyzer (Nano-DMA), which recently developed for measuring particle sizes between 2nm and 100nm and provides high-resolution size information for early soot. Particles will be also collected on transmission electron microscope (TEM) grids using rapid thermophoretic sampling and analyzed for morphology. These measurements will allow fresh and original insight into the characterizing soot inception process. The measured physical properties of incipient soot will clarify the controlling growth mechanism combined with chemical ones, and the dominant mechanism for soot modeling can be deduced from the information.

• Wind and Structures
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• v.22 no.5
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• pp.525-541
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• 2016

An offshore wind turbine supported by a spar buoy floating platform is the subject of this study on tower and rotor extreme loads. The platform, with a 120-meter draft and assumed to be sited in 320 meters of water, supports a 5 MW wind turbine. A baseline model for this turbine developed at the National Renewable Energy Laboratory (NREL) is employed in stochastic response simulations. The support platform, along with the mooring system consisting of three catenary lines, chosen for loads modeling, is based on the "Hywind" floating wind turbine concept. Our interest lies in gaining an understanding of the dynamic coupling between the support platform motion and the turbine loads. We first investigate short-term response statistics using stochastic simulation for a range of different environmental wind and wave conditions. From this study, we identify a few "controlling" environmental conditions for which long-term turbine load statistics and probability distributions are established.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.1
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• pp.67-73
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• 2023

As interest in underwater structures and ocean exploration increases, many researchers are proposing methods for modeling and controlling various remotely operated vehicles (ROVs). Recently, hybrid systems composed of an autonomous underwater vehicle and an ROV capable of remote control and autonomous navigation are being developed. In this study we introduce a method that models Ariari-aROV, an ROV consisting of five thrusters, and performs navigation. The proposed ROV can be controlled manually and by autonomous navigation when given a target point. An extended Kalman filter is utilized for sensor measurement correction for more precise navigation. The proposed method is verified through a simulation.