• Korean Journal of Cognitive Science
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• v.17 no.3
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• pp.191-206
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• 2006

Two experiments were conducted to investigate the effects of verbal working memory and the spatial working memory on children's text comprehension. The reading span and the operation span of the reading deficient children were smaller than that of the reading normal children, but the two groups did not differ in the visual span. Reading deficient children got lower score in the comprehension tests than reading normal children, and the difference was larger for the expository text than the narrative text. The involvement of visual working memory in reading narrative texts were more directly tested in Experiment 2 by asking the children do a secondary memory task before they answered the comprehension test. Reading normal children suffered more under auditory secondary memory condition for both narrative and expository texts, whereas reading deficient children suffered under visual secondary memory condition for narrative texts as well. The results of the two experiments suggested that the spatial working memory can be involved in text comprehension process, especially with reading deficient children.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6A
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• pp.484-493
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• 2009

For the flexible frequency utilization, cognitive radio technique has been prominently considered. The most important requirement in cognitive radio networks is to protect the communications of primary users. Spectrum sensing task by secondary users should be seriously considered in cognitive radio networks, since the spectrum sensing process makes their current quality of service worse. In this paper, we propose the channel sensing scheduling method that keeps the requirements for protecting the primary and guarantee the secondary user's quality of service as possible. The quality of service of secondary user is analyzed in terms of packet delay and loss while the protection-requirements in terms of sensing interval and sensing time predefined. In numerical analysis, we can get appropriate parameters which guarantee QoS in various environment. And simulation results show that this method can improve the performance, delay and the number of transmitted packets against consecutive sensing method.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.571-580
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• 2011

The purpose of this study was to evaluate the effects of secondary task such as sending text message (STM) and searching navigation (SN) using the variable indicating control of vehicle ((Medial-Lateral Coefficient of Variation, MLCV), (Anterior-Posterior Coefficient of Variation, APCV)) and motion signal (Jerk-Cost function, JC). Participants included 50s taxi drivers; 14 males and 14 females. Participants were instructed to keep a certain distance (30m) from the car ahead with constant speed (80km/hr or 100km/hr). Experiement consisted of driving alone for 1minute and driving with secondary task for 1minute. Both MLCV and APCV were significantly increased during Driving + Sending Text Message(STM) and Driving + Searching Navigation(SN) than Driving only. Also, JC was increased during Driving + STM and Driving + SN than Driving only. In this study, we found that even in the experts group who are taxi driver and have 25 years driving experience, the smoothness of motion is decreased and the control of vehicle is disturbed when they were performing secondary tasks like sending text message or searching navigation.

• Korean Journal of Cleft Lip And Palate
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• v.6 no.1
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• pp.17-25
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• 2003

Correction of the cleft-lip nasal deformity is a difficult task that requires clear understanding of the associated complex anatomy and function as well as the operation time, the selection of an operation method, On the expectation that it helps enhance understanding the current trend of cleft-rhinoplasty, authors analyzed secondary rhinoplasty between 1999 and 2002, In both the unilateral and bilateral cleft lip rhinoplasty, we reviewed the timing of repair, site of correction and it's major technique, incision or approach method, autogenous cartilage graft method, All patients with a septal deviation did not have a septal surgery, We were active in alar and nasal tip surgery and passive in septal and dorsal deformity correction, And for children, we used a conservative method but for adults, we used radical approach, Most surgeries are focused on esthetic goal and we thought that objective evaluation for nasal obstruction was needed for bener and predictable outcome.

• Journal of the Ergonomics Society of Korea
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• v.30 no.3
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• pp.403-408
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• 2011

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message(STM) and searching navigation(SN) on vehicle speed and distance during driving and brake response time during unexpected situation using a driving simulator. The participants included 19 college students; 9 males aged $25.2{\pm}1.0$ with $2.4{\pm}2.0years$ of driving experiences and 10 females aged $21.4{\pm}0.5$ with $1.3{\pm}0.5years$ of driving experiences. All subjects were instructed to keep a certain distance(30m) from the car ahead and a constant speed(100km/h). Average speed and average following distance were measured during 10 seconds before unexpected situation. Also, brake response time after unexpected situation was measured. Average speed was more decreased and average following distance was more increased during the driving with secondary tasks than driving only. Male maintained the assigned speed and distance better than female. The brake response time was faster during driving only than the driving with secondary tasks. And the brake response time of male was shorter than that of female.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.60
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• pp.177-194
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• 2013

According to the 2013 statistics, the small/medium-sized enterprises (SMEs) accounted for 99.9% of the Korean economy with 87.8% of employment. This simple figures also indicate SMEs export extension is a key task for the national economy stimulation and job creation. The SMEs export plunge has been affected by the European financial turbulence, US financial instability, developing countries like China entering foreign markets, a weak yen, etc. EXIM Bank, in this context, will need to take a more proactive attitude to provide trade finance by, for example, reviewing the business feasibility for SMEs with a lower credit rank or investigating importers' credit status, etc. Moreover EXIM Bank provides factoring service mostly to large companies and should lower its threshold for service provision to SMEs. Finally EXIM Bank should play more than a primary forfeiting market entity. It also needs to facilitate the secondary forfeiting market.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.83-85
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• 1996

Major cause of defects in steam generator tubes at nuclear power plant is the accumulation of magnetite and other byproducts of corrosion in the crevice gap between support plates and tubes. Since damaged tubes result in contamination of the secondary coolant by the radioactive primary coolant, they represent a safety hazard. Early detection of magnetite buildup is, therefore, imperative in order to take remedial measures such as chemical flushing. Although the eddy current testing is being used for the inspection of steam generator tubes, the interpretation of resulting signals is generally a difficult task. This paper uses the phase of sensor coil emf as the test signal to find a way of easier signal interpretation. Numerical study using FEM shows that the shape of resulting signal is good for identifying the relative position of the probe to the support plate, and for discreminating the different shapes and degrees of magnetite buildup in the crevice gap region.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.294-296
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• 2012

In cognitive radio ad hoc networks, secondary users need to exchange control information before data transmission. This task is not trivial in cognitive radio networks due to the dynamic nature of environment. This problem is sometime called rendezvous problem of cognitive radio network. The rendezvous problem is normally tackled by using two famous approaches: the use of common control channel (CCC) and using channel hopping (a.k.a sequence-based protocols). However, these two famous solutions form a vicious cycle while solving the rendezvous problem. The main purpose of this paper is to point out how and why this vicious cycle is formed.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.223-226
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• 1998

The control objective of steam generator water level in the secondary circuit of a nuclear power plant is to regulate the water level at the desired set point. The dynamics of steam generators is non-linear in nature. The task of modelling such plant is very difficult and especially so when plant operating conditions change frequently. In these reasons, conventional PI gains over all pover range will not work efficiently and a manual control is generally used in low power operation. Therefore the robust H$\infty$ controller design method should be required. In this paper, we design the robust H$\infty$ controller for water level control of steam generator using a mixed H$\infty$ optimization with model-matching method. Firstly we choose the desired model that has good disturbance rejection performance. Secondly we design a stabilizing controller to keep the model-matching error small and also provide sufficiently large stability margin against additive perturbations of the nominal plant.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.386-390
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• 1992

Algorithmic or kinematic singularities are inevitably a introduced if optimality criteria or augmented kinematic equations are used to resolve the redundancy of almost any manipulator with rotary joints. In this paper, a sufficient condition for a singularity-free optimal solution of the kinematic control of a redundant manipulator is derived and, specifically, algorithmic singularities are analyzed for optimality-based methods. A singularity-free space (SFS) to characterize the performance of a secondary task for a redundant manipulator using the sufficient condition for a redundant manipulator is defined. The SFS is a set of regions classified by the loci of configurations satisfying the inflection condition for manipulability measure in the Configuration space. Using SFS, the topological property of the Configuration space and the invertible workspace without singularities are analyzed.