• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.2
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• pp.1-12
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• 2013

This study reviews the current conditions of the completed 'Ecosystem Conservation Fund Return Project' sites to suggest management methods for their conservation and sustainability. For the scope of the study, five microsites of completed return projects in Seoul were selected and their project planning documents were reviewed to help with site surveying and analysis. To increase the accuracy of the site surveying and analysis, and to evaluate the management problems from different perspectives, the site managers were interviewed in-depth. The experts were surveyed as well to develop a realistic and practical improvement method. The survey results helped to categorize the post-management problems, and separate improvement methods were suggested for each category. First, the post-management guidelines are proposed for the ecosystem-based environment/ecosystem environment, user management, and monitoring. These guidelines will increase the expertise and practicality of the management principles. Second, the regulations for the participation of expert management enterprises and the development of separate monitoring or maintenance management team are suggested. These regulations will improve the participation of experts and consistency of management systems. Third, the post monitoring or maintenance management during the year after the project completion should be set as a separate project to secure budget. Furthermore, policies and/or institutions should be established to set a portion of ecosystem conservation return fund or a grant for post monitoring and maintenance management. Forth, as a way of adaptive management, at least more than three years of post-management should be evaluated under detailed categories and vigorous standard to improve the institutional operation for 'Ecosystem Conservation Fund Return Projects'.

• Korean Journal of Construction Engineering and Management
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• v.14 no.6
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• pp.78-89
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• 2013

Post-evaluation system reflects the results of performing a public construction project in the future similar public construction projects to be utilized in the planning. However, the current system simply compares the expected values, such as demand, B/C ratio, cost of construction, construction period, with the actual values after the completion of construction. In addition, most public owner does not actively conduct the post-construction evaluation tasks, so that the evaluation results has not been returned to early stage of a construction project. In this study, status of the post-construction evaluation system is investigated by a survey of the public owner and the construction project evaluation system of the United States and Japan was analyzed. This paper presents the improvement scheme of utilization of the results of the post-construction evaluation system. Through improving the post-construction evaluation system, it is expected that public agencies would easily utilize the post-construction evaluation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.4
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• pp.75-86
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• 2018

This research was thereby made to study and analysis ecological, landscape, and stability qualities of roadside cut Slopes in expressways and national highways that went through revegetation works. Also, evaluation items and framework for integrated assessment of plant structure and restored state for the maintenance were suggested. Following is the summary of the result. firstly, for stabilization of introduced native plant species on roadside cut slops, assessment on the post-project environmental management through long-term monitoring and maintenance works must be made. It signifies a form of authentic recovery and restoration by the native plants. second, current evaluation framework on the test beds is well managed with clear evaluation standards and table while its method of assessing the post management with only test bed results lacks conformity with this study site. Newly developed evaluation framework on the post construction sites is estimated to be used as assessment standards on any roadside construction sites. Third, after site investigation distinction was observed among different revegetating construction types in the long-term perspective. Due to the different duration time of vegetation state between seed-spray measures(degraded in time) and layer-spray measure(maintained), the use of coarse straw-mat mulching work or Coir net was suggested in long term maintenance of cut slopes. forth, segmentation of post environmental assessment is organized into three large categories of "ecological", "stabile", and "landscape" qualities regarding post restoration quality and stability of slope through native plants with which categories marks 50, 30, 20 points of rates. fifth, components of the post environmental assessment were segmented in twelve categories driving results from former experimental construction and newly focused items on site. In the future, it is possible to propose a customized assessment method considering the location and location of construction work if the research on the application of post-environment assessment methods for road construction surface recording is conducted systematically.

• Smart Structures and Systems
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• v.31 no.4
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• pp.311-323
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• 2023

Ever since ancient times, earthquakes have been a major threat to the civil infrastructures and the safety of human beings. The majority of casualties in earthquake disasters are caused by the damaged civil infrastructures but not by the earthquake itself. Therefore, the efficient and accurate post-earthquake assessment of the conditions of structural damage has been an urgent need for human society. Traditional ways for post-earthquake structural assessment rely heavily on field investigation by experienced experts, yet, it is inevitably subjective and inefficient. Structural response data are also applied to assess the damage; however, it requires mounted sensor networks in advance and it is not intuitional. As many types of damaged states of structures are visible, computer vision-based post-earthquake structural assessment has attracted great attention among the engineers and scholars. With the development of image acquisition sensors, computing resources and deep learning algorithms, deep learning-based post-earthquake structural assessment has gradually shown potential in dealing with image acquisition and processing tasks. This paper comprehensively reviews the state-of-the-art studies of deep learning-based post-earthquake structural assessment in recent years. The conventional way of image processing and machine learning-based structural assessment are presented briefly. The workflow of the methodology for computer vision and deep learning-based post-earthquake structural assessment was introduced. Then, applications of assessment for multiple civil infrastructures are presented in detail. Finally, the challenges of current studies are summarized for reference in future works to improve the efficiency, robustness and accuracy in this field.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.38.1-38.1
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• 2009

In this paper we present the first results of summer-time F region irregularities during low solar condition observed using the Gadanki MST radar. Echoes were observed on all 20 nights of radar observations and were mostly confined to the post-midnight hours. Echo morphology is very different from the equinoxial post-sunset plume-like features reported earlier from Gadanki. Echo SNRs are lower by 25 dB than their equinoxial post-sunset counterpart, and are quite comparable to the equinoxial irregularities in the post-midnight hours, which are essentially the decaying post-sunset irregularities. The Doppler velocities, which lie in the range of $\pm$ 100 m s-1, show upward/northward motion of the irregularities during the initial phase in contrast to the observed predominant downward/southward velocities associated with the decaying equinoxial post-midnight F region irregularities. Spectral widths of the summer echoes, which are well below 50 m s-1 and are very similar to those of the decaying equinoxial irregularities, represent the presence of weak plasma turbulence. Simultaneous observations made using a collocated ionosonde show no ionogram trace during 2200-0530 LT except for a few occasions. Weak frequency type spread F observed during midnight hours occurred without prior occurrence of range spread F. Concurrent ionosonde observations made from magnetic equatorial location Trivandrum also show very similar result and thus no height rise of the F layer during the midnight hours could be monitored. The preliminary analysis suggests that the post-midnight irregularities reported here are mostly freshly generated ones. The observations are discussed in the light of other observational results reported earlier and the current under standing on the post-midnight occurrence F region irregularities in summer.

• Journal of The Korean Association For Science Education
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• v.12 no.3
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• pp.61-76
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• 1992

The purpose of this study was to develop the instructional model and teaching material to change the middle school students'conceptions of electric current into the scientific ones and to investigate the effects of the model in actual classrooms. We identified the students' ideas and their misunderstanding about the concept of eIectic current through reviewing the literatures and our in this study. Based on the above results, we developed the instructional model and designed the teaching sequence and prepare the learning materials about the unit of the electric current in middle school Our instructional model was based on 'learning cycle' developed by Lawson, but the new stage called "exploration through qualitative questions" to elicit the students' own conceptions was inserted to it. To investigate the effects or the new teaching model, the pre- and post-test using the POE type were administered to experimental group(52 students) taught with learning cycles and control group(52 students) taught with traditional styles. The results are as follows; 1) The rates of correct. predictions was varying according to the kinds of problems. And the rates of the correct. reasons of their predictions were lower than those of the predictions. 2) The mean scores of the post-test of both groups were significantly higher than those of the pre-test. We could not find statistically significant difference in theme an score between experimental group and control group after implementation of the model. But the experimental group gained higher scores than those of the control group on two problem. Therefore, although we cannot show the prominent effects of our teaching model based on learning cycles, there are some effects of our model on changing the middle school students' conceptions of electric current.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.156-161
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• 1992

In this research a monitoring system for turning using NC information and the current of feed motor as a monitoring signal was developed. The overall system consists of modules such as learning process, NC data transmission, generation of forecast information, signal acquisition, monitoring and post process. In the learning process, the reference data and the cutting force equation necessary for monitoring are obtained from the accumulated monitoring results. In the generation of forecast information, the information of forecasted cutting forces is acquired from the cutting force equation and NC program and appended to each NC block as a monitor code. Reliability of monitoring is improved by using the monitor code in the real-time monitoring. Monitoring module is divided into two parts : the off-line monitoring where errors of NC program are checked and the on-line monitoring where the level of motor current is monitored during cutting operations. If the actual current level exceeds the limit value provided by the monitor code in the level monitoring, it is recognized as abnormal. In the event of abnormal status, the post processor sends the emergency stop signal to NC controller to stop the operation. Actual experiments have shown that the developed monitoring system works well.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1145-1152
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• 2019

In this paper, a low power current mode 12-bit ADC(: Analog to Digital Converter) is proposed to mix digital circuits and analog circuits with the advantages of low power consumption and high speed operation. The proposed 12 bit ADC is implemented by using 4-bit ADC in a cascade structure, so its power consumption can be reduced, and the chip area can be reduced by using a conversion current mirror circuit. The proposed 12-bit ADC is SK Hynix 350nm process, and post-layout simulation is performed using Cadence MMSIM. It operates at a supply voltage of 3.3V and the area of the proposed circuit is 318㎛ x 514㎛. In addition, the ADC shows the possibility of operating with low power consumption of 3.4mW average power consumption in this paper.

• IE interfaces
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• v.16 no.4
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• pp.411-420
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• 2003

This paper deals with how Korea Post establishes a nation wide network of the parcel warehouse & distribution centers(PWDC). The state-of-the-art of the parcel service business in Japan and U.S. are introduced for benchmarking purpose. Potential customers of the PWDC and their major goods are identified. Current major customers of the Korea Post were interviewed to figure out the potential demand of the PWDC service. Five-year volume estimation of the Korea Parcel Service(KPS) is presented based on the past 30-month B-C volume of the four major door-to-door delivery service companies in Korea. Yearly construction plan of the PWDCs is proposed; and the networking strategy of PWDC is discussed.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.104-106
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• 2003

In this paper, we study about the stator winding magnetization method and the magnetizing fixture magnetization method in post-assembly magnetization. Most of small electrical machine use the stator winding magnetization method but it is impossible to magnetize the permanent magnet by the stator winding magnetization method when the capacity of machine increases and the coercive force of magnet increases. And the eddy current disturbs the magnetization seriously in case of LSPM(Line Start Permanent magnet Motor) that have conductor bar in rotor. Hence, the magnetization fixture is required. So, in this paper we study about the post-assembly magnetization method that can use the stator winding magnetization method or must use the magnetization fixture magnetization method.