• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.2
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• pp.65-75
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• 2018

This study analyzes the characteristics of the urban landscape changes as a result of the introduction of private parks among the long-term uncollected urban planning facilities and enables the analysis of the characteristics of the urban landscape changes as a result of the introduction of private parks, and applied to the private park projects. The DSM with its building was established for the quantitative landscape analysis to examine the view ratio using the stacked visible analysis. The analysis showed that Jikdong Park had a high frequency of view from downtown to green due to its location, and that the development project of a private park on park and town boundaries significantly lowered the view ratio. This implies a large degree of damage to the landscape by development projects provided protection of the view as a natural landscape is of value. Chudong Park also saw its view ratio of views from downtown to the hills green area of Chudong Park was much lower than that of Jikdong Park. And it was confirmed that the ratio of view changes due to development projects was small compared to that of Jikdong Park. In other words, although Jikdong Park and Chu-dong Park were developed in a similar scale in terms of the ratio of views, they were subject to significant damage due to their location characteristics. It is also meaningful to note that the degree of change in the landscape resulting from development projects that could not be found in the assessment or review of the existing Landscape Impact. As private parks are introduced in the urban green belt, apartment development is being pushed for at the edge of the green belt. This study is meaningful in that it is derived based on the calculation that the survey results are derived based on the changes in the views on green areas that urban residents may experience as the private park project is carried out, and it should be introduced based on the calculation of the private parks.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.245-253
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• 2007

This research was performed to evaluate the airborne personal concentration of hazardouse materials during the process of ship construction and surveyed from May 23 to June 30, 2007 in Kyungnam West Distirct, Korea. The subject was 94 ship construction workers exposed to welding fume and respirable particulate. The airborne concentrations of those were compared to Permissible Exposure Limit(PEL) from the Ministry of Labor in Korea. The airborne concentration of 23 samples(48.9%) of welding fumes was less than $5mg/m^3$, that of 16 (34.0%) was between 5 and $10mg/m^3$, and that of 8 (17.0%) was greater than $10mg/m^3$. The airborne concentration of 27 (57.4%) of respirable particulate masses was less than $5mg/m^3$ and the othere are greater than $5mg/m^3$. The welding fumes were identified containing the heavy metasl such as Fe, Mn, Zn, Mg, Ca, and Cu. The respirable particulates has similiar tendency with welding fumes in the component of heavy metals. But the concentration of Ca, Cu, Cr, and Ni turned out to be higher in welding fumes. Twenty (42.6%) of the 47 samples of welding fumes were exceeded PEL. In the heavy metals in welding fumes, ten (21.3%) of the 47 samples of Mn were exceeded PEL. Based on the results, the higher airborne hazardous materials were still exposed to wokers in ship construction process. It is suggested that the appropriate engineering control be applied to minimize the exposed cocnetration in ship building processes.

• Journal of the Korea Concrete Institute
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• v.29 no.2
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• pp.169-177
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• 2017

Rather than causing damage from heat, blast, and radiation of a regular nuclear weapon, recently, it is predicted that North Korea has been inventing high altitude electromagnetic pulse (HEMP) missile in order to incapacitate electronic equipment. HEMP shielding facility is used for military purpose today. Despite the electromagnetic shielding effects from high quality compression plates, problems may include such as the possibility of electromagnetic influx resulting in the welding of the compression plates, and difficulties and high cost of construction. Therefore, in this study, a high electrical conducting material was added to the concrete experimental subject to ensure the shielding effect through electromagnetic waves to for the concrete structure, instead of building a shielding facility separately for the structure. Also, among the experimental subjects, 100 ${\mu}m$ of Iron-Aluminum alloy metal spraying coat was applied to two types with the highest shielding effect, and to two types with the lowest shielding effect. The result of the experiment indicates that experimental subjects added with a high electrical conductivity material did not meet the minimum shielding criteria of MIL-STD-118-125-1 standard, but all the experimental material applied to the metal spraying coating satisfied the minimum shielding criteria. In conclusion, it is considered that 100 µm of Iron-Aluminum alloy metal spraying coat contains high efficiency in the HEMP shielding.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.124-133
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• 2015

Electro interstitial scan shows potential as a non-invasive screening method. It can discriminate some diseases based on electric current response to induce low intensity direct current to limbs or local area of body. DDFAO was invented in France and it is claimed that multi-channel EIS(Electro Interstitial Scan) is useful for various diseases, especially, diagnoses of endocrine system such as diabetics are very effective. In this study, we verified the repeatability and sensitivity of DDFAO by using a RC phantom model and its clinical usefulness using data obtained from normal and diabetes subject groups. As a result, it showed the repeatability and the output change according to change of phantom characteristic, but it was hard to distinguish normal and patient groups non-invasively with just six surface electrodes of DDFAO. The repeatability and the clinical accuracy was not sufficient for screening or diagnostic purposes, as well. In spite of the results with low repeatability and accuracy conducted in this study, we still need further investigations to improve the EIS-based measurement method; EIS is very convenient and simple and it shows potential as a screening tool of the whole body health conditions rather than localized disease diagnosis.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.357-368
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• 2018

For well over 100 years, oil has enabled remote communities to generate electricity and enjoy the benefits of a consistent electrical supply. Relying solely on oil for electricity generation has left island and remote communities exposed to several risks and drawbacks. Oil-based electricity generation is often more expensive and subject to price volatility, which can result in the use of risky fuel hedging strategies. The residents of islands and remote communities express concern over the future impacts of climate change or insist on their opinions for the corresponding action with reduction of carbon emissions. These risks and drawbacks can be overcomed with continuing cost reductions in solar, wind, and energy storage technologies by maker. Reducing costs is not always a straightforward process, relying on more diversely and renewably arranged renewable energy sources led to reduced local construction cost in every situation reviewed in this study. In this paper, a convenient and simple design solution which will facilitate the optimum location and transmission route of renewable energy facility using GIS(Geographic Information System) is proposed. The suggested solutions exercised to the case of geomoon island using GIS and identified by local site survey.

• 대한공업교육학회지
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• v.33 no.2
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• pp.26-43
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• 2008

The purpose of this study is to survey of specialists cognition to authorize credits for the same subjects in entering a department of the same area in college among technical high school graduates. Today with generalized college education, about 80% of technical high school graduates enter college. Therefore, authorization of credits for the same subjects is necessary to reduce educational waste in terms of articulation among technical high schools, junior colleges and universities. In this study, a survey was conducted with 100 specialists in technical education, including technical high school teachers, researchers, and professors at junior college or technical college in university, getting answers from 84 subjects (81.25%). The results of this research can be summarized as follows: First, it is valid to authorize credits for all practical subjects completed in technical high school when technical high school graduates enter the same department at college but most of junior college professor unsuitable response. Second, it is valid to authorize credits through its own prescribed test for the same subjects when technical high school graduates enter the same department of engineering at junior college or technical college in university but opposed 62.5% of junior college professor. Third, it is most of respondent valid to authorize credits for the same subjects if results of its own examination for authorization by university are at a fixed level or higher when technical high school graduates are admitted as a junior at the same department in technical college of university after graduation from the same department at junior college.

• 대한공업교육학회지
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• v.36 no.1
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• pp.1-22
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• 2011

The purpose of this study was to develop and apply activity-centered STEM education program of electricity and electronics technology are in middle schools. The program was developed on the emphasis of problem solving in real world in relation to knowledge, attitude, and skill of Science, Technology, Engineering, and Mathematics. Basically the activity-centered STEM education program was developed through three steps of preparation, development and improvement. In the preparation stage the fellowing was included: (1) need analysis of student, educator, society (2) selection of integration type (3) analyzing subject matter of electricity, electronics area (4) establishing criteria for selecting activity tasks. In the development stage the fellowing was conducted: (1) selection of activity tasks (2) setting up educational goals (3) analyzing activity and clarifing the detailed activity (4) selecting program content, (5) organization of instructional content (6) statement of instructional objectives (7) structuring STEM education program In the improvement stage the fellowing was consisted of: (1) verification of validity by experts (2) execution of pilot test and field test by students and correction of program. The results of the applied the Activity-Based STEM Education Program to 'Afterschool' activities of S middle school were as follow: First, student' satisfaction level was high. Second, student' achievement in the cognitive domain, and affective domain was positive change. Third, student' problem solving ability was positive effect.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.2
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• pp.87-95
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• 1983

Trihalomethane removal efficiency by a fixed bed carbon adsorber was a subject of this study. Along with laboratory scale column operations, a simple adsorption model was developed to predict removal efficiency. The adsorption model includes an overall mass transfer coefficient, K and Freundlich adsorption constants, $K_F$ and n. Simulation results showed that increasing K and $K_F$ or decreasing n would take more loading and prolong run time of the adsorption bed. Typical S-shaped breakthrough curves were obtained from the experiments. The operational results at $20^{\circ}C$ and $25^{\circ}C$ indicated that a moderate difference in water temperature would not affect the treatment efficiency significantly. The adsorption constants determined from the column operation and the model simulation were reasonably close to those obtained from the isotherm test. It may be concluded that trihalomethane can be removed successfully by a fixed bed carbon adsorber.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.43-54
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• 1992

For shallow arches with large dynamic loading, linear analysis is no longer considered as practical and accurate. In this study, a method is presented for the dynamic analysis of shallow arches in which geometric nonlinearity must be considered. A program is developed for the analysis of the nonlinear dynamic behavior and for evaluation of critical buckling loads of shallow arches. Geometric nonlinearity is modeled using Lagrangian description of the motion. The finite element analysis procedure is used to solve the dynamic equation of motion and Newmark method is adopted in the approximation of time integration. A shallow arch subject to radial step loads is analyzed. The results are compared with those from other researches to verify the developed program. The behavior of arches is analyzed using the non-dimensional time, load, and shape parameters. It is shown that geometric nonlinearity should be considered in the analysis of shallow arches and probability of buckling failure is getting higher as arches are getting shallower. It is confirmed that arches with the same shape parameter have the same deflection ratio at the same time parameter when arches are loaded with the same parametric load. In addition, it is proved that buckling of arches with the same shape parameter occurs at the same load parameter. Circular arches, which are under a single or uniform normal load, are analyzed for comparison. A parabolic arch with radial step load is also analyzed. It is verified that the developed program is applicable for those problems.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.572-583
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• 2012

In this study, we investigated visual fatigue in i3D system and basic factors that contribute to visual fatigue in the system. i3D is a type of glasses-free display which supports elementary manual interaction of users with the display. In Experiment 1, we performed open-ended survey of visual fatigue and collected responses from observers which then were used as survey questions for visual fatigue. The questions were validated by factor analysis from which we derived fatigue measurement scale. In Experiment 2, we measured visual fatigue in various conditions using survey questions obtained from Experiment 1. Using manual interaction (present/absent), viewing distance(1/2/4m), and viewing orientation($0/28/56^{\circ}$) as three factors in within-subject design, we measured visual fatigue in each condition. The results indicated that visual fatigue deceases with farther viewing distance, but viewing orientation and manual interaction does not influence visual fatigue. Although fatigue unexpectedly decreased in an extreme viewing condition (e.g., distance 1m, orientation $56^{\circ}$), the results were obtained because of technical limitation of glasses-free 3D display. General discussion provides discussion on limits of the current study and suggestions for future research.