• Korean Journal of Clinical Pharmacy
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• v.28 no.3
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• pp.216-223
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• 2018

Objective: This study aimed to assess treatment persistence in Korean children and adolescents with attention deficit hyperactivity disorder (ADHD) and the factors influencing their adherence to ADHD pharmacotherapy. Methods: The study included patients between 6 and 18 years of age with ADHD who were taking various formulations of methylphenidate and atomoxetine on June 1, 2014. Patients were dichotomized as "persistent" or "non-persistent", depending on whether they continued ADHD therapy for 6 months (therapy persistence). We also investigated if the patients were taking the same medication(s) as before and also classified the patients as "medication persistent" or "non-persistent". Patient' characteristics were correlated with therapy persistence and medication persistence. Multiple logistic regression analyses were performed to assess potential risk factors for treatment persistence. Results: Overall, 3,317 patients were included in the analysis. A majority of patients were taking stimulants (82.0%), 16.2% were taking non-stimulants and 1.8% were taking a combination therapy of stimulants and non-stimulants. After 6 months, 2,290 patients (69.0%) continued to take medication for ADHD with 1,953 patients taking the same medication(s) as 6 months previously. Common positive factors for therapy persistence and medication persistence were identified as younger age, retardation, and developmental delay, and long-acting formulations of methylphenidate as either monotherapy or in a combination therapy may be used. Conclusion: ADHD medications were proven to improve academic performance and social skills of children. Collaboration between patients, parents, school staffs, and prescribers is required to improve the persistent use of ADHD medications.

• Structural Engineering and Mechanics
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• v.72 no.6
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• pp.689-712
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• 2019

Time-series models like AR-ARX and ARMAX, provide a robust way to capture the dynamic properties of structures, and their residuals can be effectively used as features for damage detection. Even though several research papers discuss the implementation of AR-ARX and ARMAX models for damage diagnosis, they are basically been exploited so far for detecting the time instant of damage and also the spatial location of the damage. However, the inverse problem associated with damage quantification i.e. extent of damage using time series models is not been reported in the literature. In this paper, an approach to detect the extent of damage by combining the ARMAX model by formulating the inverse problem as a multi-constrained optimization problem and solving using a newly developed hybrid adaptive differential search with dynamic interaction is presented. The proposed variant of the differential search technique employs small multiple populations which perform the search independently and exchange the information with the dynamic neighborhood. The adaptive features and local search ability features are built into the algorithm in order to improve the convergence characteristics and also the overall performance of the technique. The multi-constrained optimization formulations of the inverse problem, associated with damage quantification using time series models, attempted here for the first time, can considerably improve the robustness of the search process. Numerical simulation studies have been carried out by considering three numerical examples to demonstrate the effectiveness of the proposed technique in robustly identifying the extent of the damage. Issues related to modeling errors and also measurement noise are also addressed in this paper.

• The Journal of the Korea Contents Association
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• v.2 no.4
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• pp.51-58
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• 2002

A electronic business user is increased rapidly, and load of a electronic business system and network traffic are increased rapidly. Also, the data which included an audio and video is increasing in a electronic business system gradually, and According to this an Internet service businessman is paying for an enormous cost for management of a system and a maintenance of a line. It is brought a delay of a response speed about a service wish of a Web customer this system load and network traffic raise. Also, this decreases customer satisfaction and becomes an important factor to decrease competitive power of an e-business enterprise. In this study, we proposed the electronic business system that improved answer delay time about a Web customer in an e-business system based on the .net which was a the latest version of Microsoft company, and analyzed performance of a proposal system through an experiment. In the experiment result, the system that proposed it can have response time to have been improved and fast adaptability about various requests of a Web customer. Also, in a proposed system, a decrease gets a delay of a response speed to occur because of the multiple user done.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.4
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• pp.211-223
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• 2012

This study purposed to evaluate the influences of rival hospitals on the number of patients who visited the a study territory hospital. Spatial analysis technique was used to measure the impact of rival hospitals in study region. Selected hospitals were all medical school affiliated hospitals which were located in Daejeon metropolitan city and Chungchungnamdo. Patient data was collected from the claims data of the study hospital, and the number of inpatient and outpatients who visited the study hospital between January and June in 2008 were calculated on the smallest administrative district, Eup, Myeon, and Dong, in study region. To control the differences of regional characteristics among Eup, Myeon, Dong, socio-economic variables (total population, number of people aged over 65, number of basic livelihood security recipients, distance from the study hospital to the centroid point of each Eup, Myeon, Dong, number of business, and number of employees) were included in analysis model. These variables were collected from the annual year book of city as well as county located in study region. Cluster analysis classified the study region into three groups by using the difference of between th actual number of inpatient/outpatient and the predicted number of inpatient/outpatient in Eup, Myeon, and Dong. Most areas around the rivalry hospitals were categorized into same group. Multiple regression analysis indicated that areas around rivalry hospitals had statistically significantly negative relationship with the number of inpatients and outpatients who visited the study hospital. As the buffer size was increased from 5Km to 10Km, the standardized regression coefficients were decreased. These study results confirmed that rivalry hospitals in region had negative impacts on the performance of hospitals. It suggests that hospitals will require not only to select their location to minimize the effects of rivalry hospitals, but also to establish their strategy to cope with the rivalry's threats in their region.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.702-709
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• 2010

The performance of mass segmentation is greatly influenced by an initial position of a mass. Some researchers performed mass segmentation with the initial position of a mass given by radiologists. The purpose of our research is to find the initial position for mass segmentation and to notify the segmented mass to radiologists without any additional information on mammograms. The proposed system consists of breast segmentation by region growing and opening operations, decision of an initial seed with characteristics of masses, and mass segmentation by a level set segmentation. A seed for mass segmentation is set based on mass scoring measure calculated by block-based variances and masked information in a sub-sampled mammogram. We used a DDSM database to evaluate the system. The accuracy of mass detection is 78% sensitivity at 4 FP/image, and it reached 92% if multiple views for masses were considered.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.443-449
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• 2017

Swarm of low-cost UAVs for search mission has benefit in the sense of rapid search compared to use of single high-end UAV. As the number of UAVs forming swarm increases, not only the time for the mission planning increases, but also the system to operate UAVs has excessive burden. This paper addresses a decentralized area search algorithm adequate for multiple UAVs which takes advantages of flexibility, robustness, and simplicity. To down the cost, it is assumed that each UAV has limited ability: close-communication, basic calculation, and limited memory. In close-communication, heath conditions and search information are shared. And collision avoidance and consensus of next search direction are then done. To increase weight on un-searched area and to provide overlapped search, the score function is introduced. Performance and operational characteristics of the proposed search algorithm and mission planning logic are verified via numerical simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.767-774
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• 2007

A new transmit antenna selection and shuffling($AS^2$) method for spatially correlated double space time transmit diversity(DSTTD) systems is proposed. The proposed method allows dumb antennas and the superposition of multiple signals at the same transmit antenna, whereas the conventional methods consider the antenna shuffling(AS) only. According to the simulation result, the proposed method provides a 1.8 dB signal-to-noise ratio(SNR) gain over the conventional methods for spatially correlated transmit antennas. Although the number of candidates for $AS^2$ is much higher than that of AS, it is found that the number of candidates for $AS^2$ can be reduced to 36 by using the characteristics and properties of preprocessing matrices, and among them, only 6 candidates are almost always chosen. Next, we empirically compare the bit-error-rate (BER) performance of the proposed method with the conventional spatial multiplexing(SM) technique with antenna selection. Simulation results show that the proposed method outperforms the SM technique.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.348-358
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• 2017

The process of evaluating and selecting the best available techniques presents various characteristics for each country. In the case of EU, BAT is selected through TWG meeting after first screening, mass and energy balance, impact assessment and decision support process. Korea has proposed four principles to select BAT that can be carbon neutral for each environmental infrastructure in order to reduce greenhouse gas emissions. In order to evaluate and select the best available technique, it is necessary to differentiate the method according to whether it is a technique generally applied at the current workplace, whether it is a single technique or a combination technique, and whether it is a technology technique or management technique. In the case of a single technique, it should be evaluated whether it is a technique applied in the workplace, excessive cost, superior environmental technique over BAT, and secondary environmental pollution. In the case of multiple techniques, it is necessary to examine whether the emission standards are met and whether the pollutants can be treated at the same level as BAT. In the case of BAT candidates for management techniques, whether or not they contribute directly or indirectly to lowering the emission level of pollutants can be an important evaluation item. In the case of environmental techniques that are not generally applied in the workplace, it is recommended that the following 8 steps be carried out, including those prescribed by law. In the first stage, the list of performance evaluation factors is listed. In the second stage, the level of disposal of pollutants and the level of satisfaction with standards are listed. In the third stage, the environmental evaluation elements are listed. In the fourth stage, Is to list the economic evaluation elements, step 6 is to list the pollution and accident prevention evaluation factors, step 7 is the quantitative evaluation of the technical working group, and step 8 is BAT confirmation through deliberation of the central environmental policy committee.

• Health Policy and Management
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• v.22 no.2
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• pp.249-262
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• 2012

The purpose of this study is to investigate the determinants of intent to use the medical-application(M-APP) of smart phone of nurses working at the nursing department of two university hospitals in Korea. The independent variables used in the study are performance expectancy, effort expectancy, social influence, facilitating condition, attitude toward using technology, self efficacy, anxiety, ability to use a smart phone easily and socio-demographic characteristics. The sample used in the study consisted of 378 nurses selected from two university hospitals located in Seoul and Wonju, Korea. Data were collected with self-administered questionnaires and analyzed using multiple regression analysis. The results of this study revealed 5 independent variables of attitude toward using technology, self efficacy, anxiety, ability of using APP and interest in smart phone have the significant effect on the intent to use the M-APP. The results imply that the hospital administrators and nursing managers should try to give more chances to learn the skills of using M-APP, provide sufficient resources and establish the stable hospital information system in order for their employees to use the M-APP more easily at their working places.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1933-1954
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• 2013

Multiple wireless devices are being widely deployed in Intelligent Transportation System (ITS) services on the road to establish end-to-end connection between vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) networks. Vehicular ad hoc networks (VANETs) play an important role in supporting V2V and V2I communications (also called V2X communications) in a variety of urban environments with distinct topological characteristics. In fact, obstacles such as big buildings, moving vehicles, trees, advertisement boards, traffic lights, etc. may block the radio signals in V2X communications. Their impact has been neglected in VANET research. In this paper, we present a realistic and efficient radio propagation model to handle different sizes of static and moving obstacles for V2X communications. In the proposed model, buildings and large moving vehicles are modeled as static and moving obstacles, and taken into account their impact on the packet reception rate, Line-of-sight (LOS) obstruction, and received signal power. We use unsymmetrical city map which has many dead-end roads and open faces. Each dead-end road and open faces are joined to the nearest edge making a polygon to model realistic obstacles. The simulation results of proposed model demonstrates better performance compared to some existing models, that shows proposed model can reflect more realistic simulation environments.