• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.796-803
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• 1997

The PVT and $^2H$-NMR characteristic of main-chain dimer liquid crystals having structures such as ${\alpha}$, ${\omega}$-bis[4,4'-cyanobiphenyl) oxy] alkane(CBA-10) were studied. In this work, V-T curves obtained from isobaris measurements on various pressures, volume changes were observed at the nematic-isotropic and nematic-crystal phase transition. The volume changes at the transition exhibit slight odd-even effect with respect to the number of methylene unit n. The values of the$({\Delta}S_{tr})_V$ obtained at the NI transition for CBA-10 was $12.6J/mol{\cdot}K$. The values of $({\Delta}S_{CN})_V$ for the CN transition was estimated on the basis of DSC data : $65.3J/mol{\cdot}K$. For both transition, it was found that the correction about the volume change is significant, ranging from 40 to 60% of the total transition entropy observed under constant pressure. The RIS analysis of the spectra was performed so as to elucidate the conformational characteristics of the spacer in the nematic phase. The conformational entropy changes at both CN and NI interphases were estimated on the basis of the nematic conformations taken from the conformation map as well as those derived from the simulation. The estimated conformational entropy change values were then compared with the corresponding constant-volume entropies obtained from PVT measurements. The correspondence between both entropy values was found to be quite good in consideration of the uncertainties involved in both experiment and calculations.

• Korean Journal of Remote Sensing
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• v.29 no.4
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• pp.361-373
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• 2013

The monitoring of urban area, target detection and building reconstruction have been actively studied and investigated since high resolution X-band SAR images could be acquired by airborne and/or satellite SAR systems. This paper describes an efficient approach to reconstruct artificial structures (e.g. apartment, building and house) in urban area using high resolution X-band SAR images. Building footprint was first extracted from 1:25,000 digital topographic map and then a corner line of building was detected by an automatic detecting algorithm. With SAR amplitude images, an initial building height was calculated by the length of layover estimated using KS-test (Kolmogorov-Smirnov test) from the corner line. The interferometric SAR phases were simulated depending on SAR geometry and changable building heights ranging from -10 m to +10 m of the initial building height. With an interferogram from real SAR data set, the simulation results were compared using the method of the phase consistency. One of results can be finally defined as the reconstructed building height. The developed algorithm was applied to repeat-pass TerraSAR-X spotlight mode data set over an apartment complex in Daejeon city, Korea. The final building heights were validated against reference heights extracted from LiDAR DSM, with an RMSE (Root Mean Square Error) of about 1~2m.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.26-34
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• 2014

Highway construction is a combination of linear, repetitive, and highly equipment intensive operations. Various types of construction equipment are deployed to ensure undisrupted performance of construction, and thus productivity improvement and cost-saving can be achieved through well-thought-out planning. The selection of construction equipment is dependent upon construction sequence, site conditions, and construction methods. In the process of planning, management should consider various types of construction methods per each type of construction operation. Also, management should map out proper construction equipment operation plan that takes the construction duration and cost measures into consideration. However, limited availability of historic data from the similar types of operations has been a stumbling block to proper construction planning, making the operations performed based upon experience and intuition guided by rules-of-thumb. As a consequence, the planing phase rarely provided an adequate validity in the implementation phase. The researchers developed a process logic for each construction type that management can utilize from early phase of highway construction planning process. Moreover, derived the construction equipment combination optimized for efficiency by using the process simulation technique. The developed method is expected to be useful for the decision-making process that aims to evaluate efficiency of various process plans and to ensure optimal selection of construction equipment for highway construction projects.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.761-768
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• 2010

This paper presents an effective method to achieve the wideband waveform for high resolution SAR(Synthetic Aperture Radar) using the frequency multiplication technique. And also this paper analyzes the root causes for the spectral regrowth due to 3rd-order intermodulation in chirp bandwidth expansion scheme using quadrature modulator and frequency multipliers. The amplitude and phase imbalance requirement are defined based on the simulation results in terms of quadrature channel imbalance. This minimizes the degradation of range resolution, peak sidelobe ratio and integrated sidelobe ratio. The wideband chirp generator using the frequency multiplier and memory map scheme was manufactured and the compensation technique was presented to reduce the spectral regrowth of SAR waveform by minimizing the amplitude and phase imbalance. After I and Q channel imbalance adjustment, the carrier level reduces －28.7 dBm to －53.4 dBm. Chirp signal with 150 MHz bandwidth at S-band expands to 600 MHz bandwidth at X-band. The sidelobe levels are reduced by about 8 to 9 dB by compensating the amplitude balance between I and Q channels.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.35 no.2
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• pp.5-23
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• 2024

The seventh year of implementing online material deposit demands a systematic collection, legal and regulatory improvements, and the establishment of a long-term strategic plan for online material collection. In this study, we aimed to propose an online material collection strategy and a long-term roadmap for preserving online resources as national intellectual and cultural heritage for future generations. To achieve this, we analyzed the status of domestic and foreign libraries, related laws and regulations, and the types and collection status of online materials. Based on this analysis, we proposed practical collection standards and methods. Ultimately, a long-term roadmap and implementation plan were suggested. The long-term development plan for online material collection established a phased, concrete implementation strategy. This includes the foundation-building phase of online material collection, followed by the expansion phase, and finally reaching the maturity phase.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.815-833
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• 2016

This study investigated children's (grade 3 to 9) responses to assessment items on energy as a cross-cutting concept in order to get basic information for a learning progression. The assessment consisted of 8 ordered multiple-choice items at the contexts of electric circuit, mechanical energy of falling objects, phase change of matter, dissolution, biological phenomena of a lizard, food chain, radiative equilibrium between Sun and Earth, and the system of water cycling. Children's responses to each item were analyzed with using cross-tabulations in terms of grades and item option levels and Wright map and Differential item functioning based on Rasch modeled item response analysis. The results offered empirical evidence of children's development of understanding energy from relation between energy and its phenomena, types of energy, transfer and conversion of energy, towards conservation and equilibrium of energy for all of eight contexts. Children of each grade did not fully understand energy conservation. As grade goes up, their understandings of energy transfer and conversion were differentiated across the contexts and topics of energy. According to Rasch analysis, children had easier understanding of energy on dissolution and poorer understanding of energy on water cycling than that on other contexts. It was discussed and suggested that the results of this study help us organize science topics with regard to energy when developing new national science curriculum.

• The Journal of Korean Academy of Sensory Integration
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• v.14 no.1
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• pp.41-49
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• 2016

Objective : The purpose of this study was to investigate how undressing skill training based on Neuro-developmental treatment (NDT) approach effected on the midline orientation and protective reaction of children with cerebral palsy (CP). Methods : Two participants of this study were 3 years 5 months old boy and 4 years 5 months old girl, living in B city. They were medically diagnosed as cerebral palsy. Research design used in this study is AB design for a single subject research. There was no intervention on the baseline A phases, and functional activity based NDT was used undressing skill training during the B phases. Midline orientation was tested by Stepping subtest in MAP. Protective reaction was measured by Protective reaction subtest in QUEST. Results : In comparison with the baseline (A), midline orientation was improved above 2 standard deviations at intervention phase (B). and protective reaction was improved above averages in both hands. Conclusion : The study showed undressing skill training based on NDT approach that were effective for midline orientation of children with CP. Undressing skill training was one of the major functional activities. Thus, large studies are required to ensure the training effects.

• Journal of the Korean Geographical Society
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• v.43 no.1
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• pp.87-103
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• 2008

The geographical name is an expression of human knowledge about living conditions and a basic tool for understanding about regional cultures and history as a result of spatiotemporal changes. This study aims to understand the historical and regional characteristics by analyzing the frequency and distribution of geographical names of 1:50,000 topographic map in the early 20th century and materializing on electronic cultural atlas. The result of this analysis is as follows. First, the aspect of distributed geographical names on the Korean Peninsula reflects a general trait of the country's natural and human environment included geographical features, population, arable land, the number of counties and villages, and functions of administration and military, etc. Second, through the frequency and weight of their names, the analysis shows not only the change of native names, but also the country's phase of the time by Japanese colonial policies such as exploitation of resources, the construction of railroads, and a desire to control of the border area with Manchuria. In addition, the study identified regional characteristics and differences in environmental perception and preferences, and naming basis and forms by the comparative analysis of each type of geographical names associated with village and ridge such as 'Chi' 'Ryung' 'Duk' 'Hang' 'Pyeong' 'Gok'. In particular, those characteristics were largely affected from environmental difference of each area.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.89-96
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• 2005

As the number of the municipalities which have finished the phase I of their GIS system development projects increases, it is very natural that GIS system operation and maintenance rather than development itself has been a more important concern for these municipalities. It seems to me that these phenomena will be amplified as time goes by, and this is the right time for a series of proper guidelines regarding the GIS system maintenance to be supplied to the related municipalities. The subject which is called as 'GIS maintenance' is surely a very comprehensive area. It has been also founded that the necessity is widely agreed among the concerned people working for the municipalities which have already finished their first GIS projects. Nevertheless, it has been investigated that the studies done up to now in this area is in a very infant state from the quality and also quantity points of views. This paper, therefore, makes one of the very initial trials for the systematical GIS maintenance. Among the areas of GIS maintenance, the GIS database maintenance has been selected as the first trial area because of its natural characteristics of the basic element composing IS(Information System). For this, the present conditions of a variety of municipalities have been investigated as far as GIS maintenance is concerned, and the results are analyzed to produce a series of useful outcomes in terms of facing problems and accompanied plans. For each problem, a solution is defined and for each solution a detailed action plan (item) is derived. For each of the two kinds of GIS data given which are the fundamental map and the underground facilities map, an effective GIS data maintenance plan is suggested for the concerned municipalities.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.115-124
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• 2021

Due to the successful accomplishments of the first-stage base center project, a road-map for the second-stage, global base center 2030 project has recently been proposed. The vision of the base center is to build a technology centered, cooperation based platform for a sustainable global community. The global base center 2030 project is based on three core strategies as well as three key strategies. The main goal of the core strategy is to establish an interdisciplinary smart platform, as well as a global tech-coordination facility to implement sustainable, inclusive, and innovative science and technology based ODA projects. To achieve such goals, the global center will focus on developing a global living lab, interdisciplinary smart linkage systems, and a global operating platform. The main goals for the key strategies are to solve issues at the base centers while establishing an international relationship through sustainable technology. To achieve such goals, key projects are centered in establishing a ICT package, and a global living lab based on smart interconnected system. With this, a global inter-connected business platform will also be established to support technical and operational issues.