• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.96.3-96
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• 2002

A scheme of clarifying fault feature in the residual is given for model-based fault detection and diagnosis of control systems. It is based on the residual generation using a robust filter and the noise suppresion in test statistics of the residual by multi-scale discrete wavelet transform. By clarifying the fault feature in the residual, the difficulties of existing model based approaches via adopting a threshold can be overcomed and it has advantage of taking the false alarm and missed detection into acount at the same time, which can make the fault detection and diagnosis easy and correct. To show the effectiveness of our approach, the simulation results are illustrated for a linear syste...

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.79-87
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• 2013

An unstable yet efficient phenanthrene-degrading bacterium strain Ph-3 was isolated from a petroleum-contaminated site at the Mathura Oil Refinery, India. The strain was identified as Pseudomonas sp. using a polyphasic approach. An analysis of the intermediates and assays of the degradative enzymes from a crude extract of phenanthrene-grown cells showed a novel and previously unreported pattern of 1, 2-dihydroxy naphthalene and salicylic acid production. While strain Ph-3 lost its phenanthrene- degrading potential during successive transfers on a rich medium, it maintained this trait in oligotrophic soil conditions under the stress of the pollutant and degraded phenanthrene efficiently in soil microcosms. Although the maintenance and in vitro study of unstable phenotypes are difficult and such strains are often missed during isolation, purification, and screening, these bacteria constitute a substantial fraction of the microbial community at contaminated sites and play an important role in pollutant degradation during biostimulation or monitored natural attenuation.

• ETRI Journal
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• v.33 no.3
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• pp.466-469
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• 2011

As a fine-grained power gating method for achieving greater power savings, our approach takes advantage of the finite state machine with a datapath (FSMD) characteristic which shows sequential idleness among subcircuits. In an FSMD-based power gating, while only an active subcircuit is expected to be turned on, more subcircuits should be activated due to the power overhead. To reduce the number of missed opportunities for power savings, we deactivated some of the turned-on subcircuits by slowing the FSMD down and predicting its behavior. Our microprocessor experiments showed that the power savings are close to the upper bound.

• Cross-Cultural Studies
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• v.20
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• pp.29-66
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• 2010

This paper is a qualitative study of the experiences of Korean heritage language learners (KHLLs) with literacy (reading and writing), particularly before they enter the college-level heritage language classroom. Previous research, both qualitative and quantitative, has addressed the overall language background of KHLLs, including oral and aural proficiency and writing and reading ability, as well as demographic information (such as when the student immigrated to the United States) in relation to language test scores. This study addresses KHLL experiences in the following six areas as they relate to student perceptions and attitudes toward their own heritage language literacy: language proficiency, motivation for learning, academic preparedness, cultural connectedness, emotional factors, and social factors. Fourteen undergraduate students at a university in the western United States participated in a convenience sample by responding to a 10-question survey. Trends in responses indicated that KHLLs entered the classroom with high integrational motivation and experienced great satisfaction with perceived progress in literacy, but students also expressed regret for having missed childhood learning experiences that would likely have resulted in higher proficiency. These experiences include informal and formal instruction in the home and formal instruction outside of the home.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.55-66
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• 2002

In many countries the principle of shielding is employed to permit a more logical approach to restricting new construction and prescribing obstacle marking and lighting. It also reduces the number of cases of new construction requiring review by authorities. Shielding principles are employed when some object, an existing building or natural terrain, already penetrates above one of the obstacle limitation surfaces described in Annex 14. If it is considered that the nature of an object is such that its presence may be permanent, then additional objects within a specified area around it may be permitted to penetrate the surface without being considered as obstacle. The shielding effect of immovable obstacles laterally in final approach and missed approach areas is more uncertain. In certain circumstances, it nay be advantageous to preserve existing unobstructed cross section areas, particularly when the obstacle is close to the runway. This would guard against future changes in either approach or take-off climb area specifications or the adoption of a turned take-off procedure.

• Journal of the Korea Society for Simulation
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• v.21 no.3
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• pp.1-9
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• 2012

This paper proposes automatic precision approach radar (PAR) control system using digital signal to increase the safety of aircraft, and discrete event systems specification (DEVS) methodology is utilized to verify the proposed system. Traditionally, a landing aircraft is controlled by the human voice of a final approach controller. However, the voice information can be missed during transmission, and pilots may also act improperly because of incorrectness of auditory signals. The proposed system enables the stable operation of the aircraft, regardless of the pilot's capability. Communicating DEVS (C-DEVS) is used to analyze and verify the behavior of the proposed system. A composed C-DEVS atomic model has overall composed discrete state sets of models, and the state sequence acquired through full state search is utilized to verify the safeness and the liveness of a system behavior. The C-DEVS model of the proposed system shows the same behavior with the traditional PAR control system.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.37.1-37.1
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• 2019

The faint quasars with M1450 > -24 mag are known to hold the key to the determination of the ultraviolet emissivity for the cosmic reionization. But only a few have been identified so far because of the limitations on the survey data. Here we present the first results of the z ~ 5 faint quasar survey with the Infrared Medium-deep Survey (IMS), which covers ${\sim}100deg^2$ areas in J band to the depths of $J_{AB}$ ~ 23 mag. To improve selection methods, the medium-band follow-up imaging has been carried out using the SED camera for QUasars in Early uNiverse (SQUEAN) on the Otto Struve 2.1 m Telescope. The optical spectra of the candidates were obtained with 8 m class telescopes. We newly discovered 10 quasars with -25 < $M_{1450}$ < -23 at z ~ 5, among which three have been missed in a previous survey using the same optical data over the same area, implying the necessity for improvements in high-redshift faint quasar selection. We derived photometric redshifts from the medium-band data and found that they have high accuracies of ${\langle}{\mid}{\Delta}z{\mid}/(1+z){\rangle}=0.016$. The medium-band-based approach allows us to rule out many of the interlopers that contaminate ${\geq}20%$ of the broadband-selected quasar candidates. These results suggest that the medium-band-based approach is a powerful way to identify z ~ 5 quasars and measure their redshifts at high accuracy (1%-2%). It is also a cost-effective way to understand the contribution of quasars to the cosmic reionization history.

• International Journal of Contents
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• v.10 no.4
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• pp.11-17
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• 2014

The influence of acquisition environment on music score images captured by a camera has not yet been seriously examined. All existing Optical Music Recognition (OMR) systems attempt to recognize music score images captured by a scanner under ideal conditions. Therefore, when such systems process images under the influence of distortion, different viewpoints or suboptimal illumination effects, the performance, in terms of recognition accuracy and processing time, is unacceptable for deployment in practice. In this paper, a novel, lightweight but effective approach for dealing with the issues caused by camera based music scores is proposed. Based on the staff line information, musical rules, run length code, and projection, all regions of interest are determined. Templates created from inverse filter are then used to recognize the music symbols. Therefore, all fragmentation and deformation problems, as well as missed recognition, can be overcome using the developed method. The system was evaluated on a dataset consisting of real images captured by a smartphone. The achieved recognition rate and processing time were relatively competitive with state of the art works. In addition, the system was designed to be lightweight compared with the other approaches, which mostly adopted machine learning algorithms, to allow further deployment on portable devices with limited computing resources.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.620-624
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• 1984

The optimal surgical management of the coarctation of the aorta associated with ventricular septal defect is still debated. Sixteen patients with the coarctation of the aorta and VSD were operated upon between November, 1980 and September 1984 at Seoul National University Hospital. They were 11 males and 5 females. All presented between 5 months and 11.5 years of age [mean= 5.5 years]. Presenting symptoms were congestive heart failure in 11 [69%], cyanosis on crying in 3 [19%], and frequent upper respiratory infection in 2 [13%]. In all cases two-stage operation was applied except one in which one stage procedure was taken. Resection and end-to-end anastomosis was used in 3, Dacron graft in 5, Gortex graft in 1, and left subclavian flap angioplasty in 4. Remaining two were missed on the operating table before correction of the coarctation of the aorta. Overall operative death in repair of the coarctation of the aorta were 3[20%]. Among the 12 survivors after repair of the coarctation of the aorta, 4 required patch closure of VSD, 2 required primary closure, 2 showed spontaneous closure [17%], one [8%] showed decrease in its size, 3 were under observation. It might be safe to approach the coarctation of aorta plus VSD with initial repair of the coarctation of the aorta without banding of main pulmonary artery and later management of VSD as usual manner in simple VSD.

• Journal of Distribution Science
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• v.15 no.7
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• pp.19-24
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• 2017

Purpose - There are several problems that organizations face to make a better team-based system such as free-rider issue, assigned difficult jobs unfairly and bickering between high performers and average performers. The purpose of this study is to provide solutions for practitioners through past academic studies on how organizations can resolve several issues in team management. Ultimately, it would lead to employees as better performers for organization's profitability and customers' satisfaction. Research design, data, and methodology - Solution 1 - put employees who have a similar performance ability together into a same team and apply 'growth' approach for low performance team. Solution 2 - make a new evaluation system which is balanced between individual's performance and team's performance. Solution 3 - monitor thoroughly to diffuse difficult works equally among teams and develop management practice system that may prevent or resolve difficult work-loads for a team or an individual performer. Result - Investigation suggests that organizations may resolve three conflicts which come from team base system. Moreover, the implications of results show that the most important criteria in team management depend on whether performers have a similar ability in the same team and management handles issue of justice and the performance of each employee is evaluated by total team performance evaluation simultaneously. Conclusions - All in all, our recommendation concludes that if three issues are resolved, the lack of trust in team-based system among team members will be missed.