• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.58-58
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• 2011

The Texas Commission on Environmental Quality(TCEQ) WAM(Water Availability Modeling) System consists of the generalized Water Rights Analysis Package(WRAP) river/reservoir system water management simulation model, 22 sets of WRAP hydrology and water rights input files for the 23 river basins of Texas, geographic information system tools, and other supporting databases. The WRAP/WAM modeling system, as routinely applied since the late 1990s, has not included consideration of water quality. Recently developed WRAP-SALT(Water Rights Analysis Package) is designed primarily for computing concentration frequency statistics and supply reliability indices at locations of interest in a river system for alternative water development and management scenarios. Though motivated primarily by natural salt pollution, WRAP-SALT water quality modeling features are applicable to essentially any conservative water quality constituent. The Brazos River studies discussed in this paper focus on total dissolved solids, though the available observed data also includes chloride and sulfate which can be modeled as individual constituents. The WRAP-SALT salinity input file contains loads or concentrations of salinity inflows during each month of the hydrologic period-of-analysis and reservoir storage at the beginning of the simulation. The WRAP-SALT model computes salt loads and concentrations for each control point of a river/reservoir system for inflows and outflows during the month and end-of-month reservoir storage for each month of the hydrologic period-of-analysis, for given loads entering the system. River reaches connect control points. The mass balance algorithms proceed from upstream to downstream, with outflow from one river reach contributing to inflow to the next downstream reach. In a given month, for each control point in sequence, the inflow loads are first computed. Loads and concentrations of outflows and reservoir storage at the control point are then determined. Complete mixing during the month is assumed at locations without reservoir storage.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.3
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• pp.138-146
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• 2010

It is well known that many biological networks are very robust against various types of perturbations, but we still do not know the mechanism of robustness. In this paper, we find that there exist a number of feedback loops in a real biological network compared to randomly generated networks. Moreover, we investigate how the topological property affects network robustness. To this end, we properly define the notion of robustness based on a Boolean network model. Through extensive simulations, we show that the Boolean networks create a nearly constant number of fixed-point attractors, while they create a smaller number of limit-cycle attractors as they contain a larger number of feedback loops. In addition, we elucidate that a considerably large basin of a fixed-point attractor is generated in the networks with a large number of feedback loops. All these results imply that the existence of a large number of feedback loops in biological networks can be a critical factor for their robust behaviors.

• Journal of Convergence for Information Technology
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• v.12 no.5
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• pp.150-158
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• 2022

The purpose of this study is to confirm the effectiveness of the evaluation of long-term care insurance visiting care service institutions for the elderly from the user's point of view. To this end, data from a survey of 266 users collected through allocation sampling by region(14 cities and counties) in Jeollabuk-do and public data from 47 institutions were combined and analyzed using a multi-layered model. The main research results are as follows. First, among the five evaluation areas, the higher the score in the 'Rights·Responsibility' area, which is to give users a sense of rights and respect users, the higher the service quality and satisfaction. Second, among the five evaluation areas, the 'Rights·Responsibility' area had an effect on loyalty. In addition, it was found that the 'Outcome' area for satisfaction with institutions and employees and changes in users had an effect on loyalty. Third, it was found that 'Institutional Management', 'Environment·Safety', 'Process' did not affect service quality, satisfaction, and loyalty. Based on these results, it is proposed to reorganize the evaluation scale that users can recognize and that is faithful to the purpose.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.1
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• pp.55-64
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• 2023

Gas turbine engines are widely used as prime movers of generator and propulsion system in warships. This study addresses the problem of designing a DS-based PID controller for speed control of the LM-2500 gas turbine engine used for propulsion in warships. To this end, we first derive a dynamic model of the LM-2500 using actual sea trail data. Next, the PRC (process reaction curve) method is used to approximate the first-order plus time delay (FOPTD) model, and the DS-based PID controller design technique is proposed according to approximation of the time delay term. The proposed controller conducts set-point tracking simulation using MATLAB (2016b), and evaluates and compares the performance index with the existing control methods. As a result of simulation at each operating point, the proposed controller showed the smallest in %OS, which means that the rpm does not change rapidly. In addition, IAE and IAC were also the smallest, showing the best result in error performance and controller effort.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.8
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• pp.321-328
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• 2014

In this paper, we present a MapReduce-based mobility pattern mining system which can predict efficiently the next place of mobile users. It learns the mobility pattern model of each user, represented by Hidden Markov Models(HMM), from a large-scale trajectory dataset, and then predicts the next place for the user to visit by applying the learned models to the current trajectory. Our system consists of two parts: the back-end part, in which the mobility pattern models are learned for individual users, and the front-end part, where the next place for a certain user to visit is predicted based on the mobility pattern models. While the back-end part comprises of three distinct MapReduce modules for POI extraction, trajectory transformation, and mobility pattern model learning, the front-end part has two different modules for candidate route generation and next place prediction. Map and reduce functions of each module in our system were designed to utilize the underlying Hadoop infrastructure enough to maximize the parallel processing. We performed experiments to evaluate the performance of the proposed system by using a large-scale open benchmark dataset, GeoLife, and then could make sure of high performance of our system as results of the experiments.

• Journal of Information Technology Services
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• v.19 no.1
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• pp.113-127
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• 2020

Current web accessibility checks and automatic assessments have been pointed out that the assessment items and scores are evaluated from the developer's point of view rather than from the user's one. In addition, although most of the grades of an automatic assessment on the public web sites are excellent because they are built in accordance with the web accessibility development guidelines, not a few web sites shows relatively low grades in evaluating their usability test made by those users. Taking into account the inadequacy of these web accessibility assessments, this study has identified the differences between the grades of usability evaluations and automatic evaluations for people with low vision and analyzed the major factors affecting web accessibility usability evaluations using Repertory Grid Techniques. Also, the Hard Laddering method of the Means-End Chain theory was adopted to visualize the relationship between Attributes-Conferences-Value and a hierarchical value system analysis based on FGI(Focused Group Interview) to people with the low vision. This study proposed the measures to improve the current web accessibility automatic assessment allocation, expert evaluation criteria, and user task assessment. In particular, it is a web accessibility user evaluation model that can consider the web accessibility quality certification criteria and user review assessment by directly analyzing the user cognitive structure and value system. This study is expected to be useful as a research to enhance the quality of web accessibility assessment.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.2
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• pp.30-38
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• 2003

This paper proposed PID controller for torch slider and PD controller for motor right wheel. to control the motion of two-wheeled welding mobile robot with seam tracking sensor touched on welding line. The motion control is realized in the view of keeping constant welding velocity and precise seam tracking even though the target welding line is on straight line or curved line. The position and direction of the body of the mottle robot are controlled by using signal errors between seam tracking sensor and body positioning sensor attached on the end of torch slider and body side of the mobile robot, respectively. In turning motion, the body and the torch slider are controlled by using the kinematic model related with two motions of body turning and torch sliding. The straight locomotion is controlled according to eleven control patterns obtained from displacements between two sensors of the seam tracking sensor and the body positioning sensor. The effectiveness is proven through the experimental results fur lattice type welding line. Through the experimental results, we can see that the position value of the electrode end point and the welding velocity are controlled almost constantly both in straight and turning locomotion.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.59-65
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• 1998

Instead of brilliant advancement of the organ transplantation in the medical fields, laryngeal transplantation still has couple of problems to be solved before trial on human. Among them functional restoration of the implanted larynx is the most important point. Recent advancement in animal model studies showed possibility of solving the main problem. Eighteen cases of canine laryngeal transplantation in mongrel dogs were done in this department. One cranial artery and two external jugular veins were connected. External and internal branches of the superior layngeal nerve and anterior and posterior branches of the recurrent laryngeal nerve were connected individually. Only two dogs have lived longer than 4 weeks(4weeks, and 10 1/2weeks) and they died unfortunately due to asphixia caused by obstruction of the cannula. Thirteen dogs only lived five days through 15 days. The main causes of the failure were obstruction of the connecting vein, pharyngocutaneous fistula and the wound infection. Although the result was not good enough to evaluate the functional restoration of the implanted larynx, the implanted larynges from the two dogs lived longer than minimum criteria of long term survival(4 weeks) were relatively good in shape at the time of autopsy. This program will be continued after renovation of the animal lab. facilities.

• Computational Structural Engineering
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• v.10 no.4
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• pp.177-184
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• 1997

In this paper, numerical methods are developed for solving the elastica of simple beams with variable-arc-length subjected to a point loading. The beam model is based on Bernoulli-Euler beam theory. The Runge-Kutta and Regula-Falsi methods, respectively, are used to solve the governing differential equations and to compute the beam's rotation at the left end of the beams. Extensive numerical results of the elastica responses, including deflected shapes, rotations of cross-section and bending moments, are presented in non-dimensional forms. The possible maximum values of the end rotation, deflection and bending moment are determined by analyzing the numerical data obtained in this study.

• Structural Engineering and Mechanics
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• v.54 no.3
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• pp.433-451
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• 2015

This paper focuses on large deflection static behavior of edge cracked simple supported beams subjected to a non-follower transversal point load at the midpoint of the beam by using the total Lagrangian Timoshenko beam element approximation. The cross section of the beam is circular. The cracked beam is modeled as an assembly of two sub-beams connected through a massless elastic rotational spring. It is known that large deflection problems are geometrically nonlinear problems. The considered highly nonlinear problem is solved considering full geometric non-linearity by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. There is no restriction on the magnitudes of deflections and rotations in contradistinction to von-Karman strain displacement relations of the beam. The beams considered in numerical examples are made of Aluminum. In the study, the effects of the location of crack and the depth of the crack on the non-linear static response of the beam are investigated in detail. The relationships between deflections, end rotational angles, end constraint forces, deflection configuration, Cauchy stresses of the edge-cracked beams and load rising are illustrated in detail in nonlinear case. Also, the difference between the geometrically linear and nonlinear analysis of edge-cracked beam is investigated in detail.