• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.313-326
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• 2018

This paper introduces core techniques on ship detection and tracking based on a compact HF radar platform which is necessary to establish a wide-area surveillance network. Currently, most HF radar sites are primarily optimized for observing sea surface radial velocities and bearings. Therefore, many ship detection systems are vulnerable to error sources such as environmental noise and clutter when they are applied to these practical surface current observation purpose systems. In addition, due to Korea's geographical features, only compact HF radars which generates non-uniform antenna response and has no information on target information are applicable. The ship detection and tracking techniques discussed in this paper considers these practical conditions and were evaluated by real data collected from the Yellow Sea, Korea. The proposed method is composed of two parts. In the first part, ship detection, a constant false alarm rate based detector was applied and was enhanced by a PCA subspace decomposition method which reduces noise. To merge multiple detections originated from a single target due to the Doppler effect during long CPIs, a clustering method was applied. Finally, data association framework eliminates false detections by considering ship maneuvering over time. According to evaluation results, it is claimed that the proposed method produces satisfactory results within certain ranges.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.1
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• pp.1-7
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• 1997

We have monitored nutrients, chlorophyll, suspended solids, and salinity in the Keum Estuary to understand the temporal fluctuation of oceanographic parameters and to illustrate any variation due to the gate operation of the Keum River Dike from June, 1995 to September, 1996, approximately for 500 days. Tidal range is used as the key factor to explain the fluctuations and atmospheric parameters such as air temperature, wind velocity and rainfall are also used supplementally. The fresh water discharge was selected as another major impact on the estuarine environment due to the gate operation of the Keum Dike. In addition, daily variation by tidal cycle was investigated twice in April and July, 1996. In diurnal variation, salinity was positively correlated with tidal elevation, whereas negatively correlated with nutrients. Relatively high suspended solid and chlorophyll contents were found in the period between high and low tide. In 500 days continuous observations, salinity was negatively correlated with the volume of fresh-water discharge, but positively correlated with nutrients. A major chlorophyll bloom occurred in spring. A similar pattern of variation was observed between suspended solid and the neap-spring tidal cycle. In comparison with the data of the Keurn Estuary before the gate operation of the Keum River dike, fresh-water discharge predominated other environmental factors during the rainy season. In addition, the velocity of tidal current and the concentration of suspended solid were decreased, while nutrients and chlorophyll contents were increased.

• Journal of Engineering Education Research
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• v.4 no.1
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• pp.57-78
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• 2001

Due to developments in information technology and ensuing changes in the concept of time and space, the significance of national boundaries has been weakened, bringing to attention the heightened competition among nations. In order to respond to these transformations, the Korean government is increasing its efforts to raise the authenticity of the National Technology Qualification System(NTQS) by closely linking NTQS testing method and procedure to practical knowledge and skills in the industry field. This initiative is based on the recognition that the human resources development is a crucial factor in determining a nation's competitiveness. This study aimed, first of all, to diagnose the problems directly and indirectly affecting the testing method in the current NTQS. And then, differentiated solutions according to grade and improvements in the testing infrastructure were suggested. The ultimate purpose was to provide a blueprint for enhancing national competitiveness through increased authenticity and efficiency of the NTQS. Research methods applied during this study include: the collection and review of qualification-related literature; a series of conferences with leading experts; interviews with vocational educators and researchers from qualification-related institutes; a survey of national qualification holders from a variety of professions and industries; and participatory observation at qualification exam centers. This research suggested policy recommendations as follows; First, measures to improve for testing method of professional engineer Second, measures to improve for testing method of Master craftsman Third, measures to improve for testing method of Engineer, Industrial Engineer, Craftsman Fourth, plans for the establishment of operation system for a computerized testing Fifth, institutional perspective on establishing qualification infrastructure Sixth, operational perspective on establishing qualification infrastructure

• Journal of Engineering Education Research
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• v.12 no.1
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• pp.64-72
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• 2009

The objective of the current study is to establish the CQI procedure of leadership outcome education, which is emphasized in engineering education accreditation. Leadership includes many program outcomes, especially soft skills, such as communication skill, team work skill, and etc. This paper studied leadership education program in Yeungnam University. In particular, this research was conducted by using focus group interviews with experts and working level staffs of relevant organizations for the analysis of Yeungnam University curriculum and non-curriculum courses related to leadership education and for the preparation of leadership education CQI method. In addition, we conducted leadership competence diagnosis, leadership education demand survey and satisfaction level survey on the leadership camp participants. Interviews with experts, lecturers and focus group of Dale Carnegie Research Institute Daegu branch that administered the progress of leadership camp were conducted along with analysis of education contents through non-participation observation method during camp period and participant students interviews. The conclusions are summed up as follows: To educate global leaders in true meaning, first, psychological level competence strengthening method and study completing ability improvement method should be considered simultaneously. In particular, for non-capital region universities, emphasis should be given to education for self-confidence and vision establishment. Second, leadership education methods of mid/long term and systematic curricular and extra-curricular type should be pursued. For instance, with the use of engineering design subject completing system, leadership education can be consolidated to engineering subject courses with engineering design projects or the system of mentor-pupil among earlier leadership camp participants and later participants may be utilized. Third, it is determined necessary to pursue and realize practical methods of conducting various intramural leadership related education activities in mid/long term perspective by organizing leadership education advisory group consisting of major, departments and intramural and extramural relevant organization authorities that focus on leadership education.

• Journal of Surface Science and Engineering
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• v.53 no.2
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• pp.59-66
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• 2020

Effects of Na₂SiO₃ concentration added into 0.1 M NaOH + 0.05 M NaF solution on the formation behavior and properties of PEO films on AZ91 Mg alloy were investigated under 1200 Hz of alternating current (AC) by voltage-time curves, in-situ observation of arc generation behavior and measurements of film thickness, surface roughness and micro vickers hardness. In the absence of Na₂SiO₃ in the 0.1 M NaOH + 0.05 M NaF solution, about 4 ㎛ thick PEO film was formed within 1 min and then PEO film did not grow but white spots were formed by local burning. Addition of Na₂SiO₃ up to 0.2 M caused more increased formation voltage and growth of PEO film with uniform generation of arcs. Addition of Na₂SiO₃ from 0.2 M to 0.4 M showed nearly the same voltage-time behavior and uniform arc generation. Addition of Na₂SiO₃ more than 0.5 M resulted in a decrease of formation voltage and non-uniform arc generation due to local burning. PEO film growth rate increased with increasing added Na₂SiO₃ concentration but maximum PEO film thickness was limited by local burning if added Na₂SiO₃ concentration is higher than 0.5 M. Surface roughness of PEO film increased with increasing added Na₂SiO₃ concentration and appeared to be proportional to the PEO film thickness. PEO film hardness increased with increasing added Na₂SiO₃ concentration and reached a steady-state value of about 930 H_V at more than 0.5 M of added Na₂SiO₃ concentration.

• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.107-118
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• 2013

In this paper, we developed the semiconductor monitoring system for the etching process. Around the world, expert companies are competing fiercely since the semiconductor industry is a leading value-added industry that produces the essential components of electronic products. As a result, many researches have been conducted in order to improve the quality, productivity, and characteristics of semiconductor products. Process monitoring techniques has an important role to give an equivalent quality and productivity to produce semiconductor. In fact, since the etching process to form a semiconductor circuit causes great damage to the semiconductors, it is very necessary to develop a system for monitoring the process. The proposed monitoring system is mainly focused on the dry etching process using plasma and it provides the detailed observation, analysis and feedback to managers. It has the functionality of setting scenarios to match the process control automatically. In addition, it maximizes the efficiency of process automation. The result can be immediately reflected to the system since it performs real-time monitoring. UI (User Interface) provides managers with diagnosis of the current state in the process. The monitoring system has diverse functionalities to control the process according to the scenario written in advance, to stop the process efficiently and finally to increase production efficiency.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.351-358
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• 2016

Consistent with a previous study on the brown planthopper Nilaparvata lugens (BPH) (Seo et al., 2009), we identified seven distinct EPG waveforms (np, L1, L2, L3, L4-a, L4-b, and L5) in adult female Laodelphax striatellus (SBPH) that fed on rice plants, by using the direct current electrical penetration graph (DC-EPG) system. The shape of waveforms and the pattern of occurrence of each waveform of SBPH were very similar to those of BPH. L3 and L4-a always occurred prior to L4-b. Periodical honeydew excretion was observed in L4-b only. Microsection observation following laser stylectomy revealed that the tips of SBPH stylets severed in L3, L4-a, and L4-b were commonly located in or near the phloem region of rice plants, but were located in the xylem in L5. Plant sap flowed from the stylets severed in L4-b only, and its main carbohydrate component was detected as sucrose by HPLC analysis. These results and the patterns of EPG waveform progress in SBPH suggested that feeding activities on rice plant tissue were relevant to each EPG waveform. L1 and L2 corresponded to the initiation of stylet penetration and stylet movement with salivation on the outside of the vascular bundle. L3 and L4-a were related to feeding activities within the phloem region in preparation for phloem sap ingestion. L4-b was closely associated with phloem sap ingestion, and L5 corresponded to xylem feeding behavior.

• Journal of The Korean Association of Information Education
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• v.22 no.5
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• pp.519-533
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• 2018

This study aims to classify the types of instructional expertise development activities of teachers who teach subjects related to software education in primary schools. To this end, the study analyzes their participation in expertise development activities over the recent three years, outcomes from these activities, and forms and characteristics of expertise development activities. In the questionnaire survey conducted for this study, 276 primary school teachers participated. According to the survey, the same largest proportion of them participated in collective job training (96%) and distant job training (96%), followed by consulting, instruction supervision, mentoring, and peer observation (82%), lectures, workshops, and seminars held by related government ministries and the provincial and municipal offices of education (69%), and teachers' study communities (66%). Among informal activities, reading accounted for the highest portion of the activities (88%), followed by the use of information on Websites including YouTude and GitHub (80%), and teachers' expertise development networks (76%). The reasons for their participation in the activities were mostly to improve their instructional expertise (80%). Their participation in the activities had an impact on usefulness to enhance instructional expertise, improvement of job competencies, application to current jobs, sense of instructional efficacy, and positive effect. These results of the study are expected to provide a foundation for preparing continued expertise development plans that can promote the educational value of primary school teachers' instructional expertise development activities for teaching subjects related to software education.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.395-404
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• 2018

This research evaluated the change in rainfall quantile during S1, S2, and S3 by using Representative Concentration Pathways (RCP) 4.5 climate scenario HadGEM3-RA Regional Climate Model (RCM) produced by downscaling and bias correlation compared to the past standard observation data S0. Also, the maximum flood peak volume and flood area were calculated by using the urban runoff model and the impact of climate change was analyzed in each period. For this purpose, Gumbel distribution was used as an appropriate model based on the method of maximum likelihood. As a result, in the case of the 10 year-frequency which is the design of most urban drainage facilities, the rainfall quantile is in increased about 10% if we assume 50 years from now with the $3^{rd}$ quarter value and about 20% if we assume 70 years from now. This result implies that the installed urban drainage facility based on the currently set design flood volume cannot be met the design criteria in the future. Therefore, it is necessary to reflect future climate conditions to current urban drainage facilities.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.49.1-49.1
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• 2014

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument onboard NEXTSat-1 which is being developed by KASI. The imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, star-forming regions and so on will be performed on orbit. After the System Requirement Review, the optical design is changed from on-axis to the off-axis telescope which has a wide field of view (2 deg. ${\times}$ 2 deg.) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. The mechanical structure is considered to endure the launching condition as well as the space environment. The design of relay optics is optimized to maintain the uniform optical performance in the required wavelength range. The stray light analysis is being made to evade a light outside a field of view. The dewar is designed to operate the infrared detector at 80K stage. From the thermal analysis, we confirmed that the telescope can be cooled down to around 200K in order to reduce the large amount of thermal noise. Here, we report the current status of the NISS development.