• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.80-87
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• 2006

SONY corporation preoccupies $80\%$ of a market of the CCD used in a CCTV system. The CCD of SONY have high duality which can not follow the progress of capability. But there are some problems which differ the clock frequency used in CCD from the frequency used in common video encoder. To get the result by using common video encoder, the system needs a scaler that could adjust image size and PLL that synchronizes CCD's with encoder's clock So, this paper proposes the video encoder that is activated at equal clock used in CCD without scaler and PLL. The encoder converts ITU-R BT.601 4:2:2 or ITU-R BT.656 inputs from various video sources into NTSC or PAL signals in CVBS. Due to variable clock, property of filters used in the encoder is automatically changed by clock and filters adopt multiplier-free structures to reduce hardware complexity. The hardware bit width of programmable digital filters for luminance and chrominance signals, along with other operating blocks, are carefully determined to produce hish-quality digital video signals of ${\pm}1$ LSB error or less. The proposed encoder is experimentally demonstrated by using the Altera Stratix EP1S80B953C6ES device.

• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.3-12
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• 2014

With the scale of program management getting larger and complexity, More accurate and precise method for management cost estimate is demanded. However, most of project management cost estimates are based on similar cases and hence can not reflect distinct features of each project. Cost estimate precision is also not up to the standards, and also troublesome to policy-making and budget allocation. Therefore, project typical model for cost estimate of Comprehensive Project Management is developed, and makes it easier to manage level of effort and allocate cost by applying characteristic factor of each project. This study categorized the project package by phase; planning, detailed design, and bid procurement, to develop typical model. And by designating specific level of effort required for each field and rank, the study aims to improve the method for calculating the detailed and objective program cost. Outcome of this study will prevent conflicts between client and contractor, accurately calculate program management contract cost for the client, and become a reference for the contractor to receive rational and practical payments for their work.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.878-891
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• 2011

We consider the throughput-maximization problem for both the up- and downlink in a wireless network with interference channels. For this purpose, we design an iterative and distributive uplink algorithm based on Lagrangian relaxation. Using the uplink power prices and network duality, we achieve throughput-maximization in the dual downlink that has a symmetric channel and an equal power budget compared to the uplink. The network duality we prove here is a generalized version of previous research [10], [11]. Computational tests show that the performance of the up- and downlink throughput for our algorithms is close to the optimal value for the channel orthogonality factor, ${\theta}{\in}$(0.5, 1]. On the other hand, when the channels are slightly orthogonal (${\theta}{\in}$(0, 0.5]), we observe some throughput degradation in the downlink. We have extended our analysis to the real downlink that has a nonsymmetric channel and an unequal power budget compared to the uplink. It is shown that the modified duality-based approach is thoroughly applied to the real downlink. Considering the complexity of the algorithms in [6] and [18], we conclude that these results are quite encouraging in terms of both performance and practical applicability of the generalized duality theorem.

• Fire Science and Engineering
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• v.34 no.2
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• pp.72-85
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• 2020

This article is a study on the activity of rescue workers for designing simulation training scenarios assuming chemical accidents. On the basis of the complexity of the indoor scene in the case of chemical accidents and terrorism, we designed a 12-step simulation training scenario for two teams to analyze the improvement in firefighters' capabilities. On the basis of activity measurement in the simulation scenario, step 2 of training had the most drops in the maximum heart rate, as follow: N1, from 163 bpm to 153 bpm; N2, from 186 bpm to 151 bpm; N3, from 168 bpm to 162 bpm; and N4, from 166 bpm to 152 bpm. In terms of intensity level in the allowable activity time, it was found that in step 2 both N1 and N2 reduced from Level 5 to Level 3, N3 remained at Level 4, N4 reduced from Level 4 to Level 3, and the maximum allowable activity time increased.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.128-136
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• 2011

To monitor and predict the change of coastal environment according to the construction of Saemangeum sea dyke and the development of land reclamation, we have done real-time and periodic ocean observation and numerical simulation since 2002. Saemangeum coastal environmental data can be largely classified to marine meteorology, ocean physics and circulation, water quality, marine geology and marine ecosystem and each part of data has been generated continuously and accumulated over about 10 years. The collected coastal environmental data are huge amounts of heterogeneous dataset and have some characteristics of multi-dimension, multivariate and spatio-temporal distribution. Thus the implementation of information system possible to data collection, processing, management and service is necessary. In this study, through the implementation of Saemangeum coastal environmental information system using geographic information system, it enables the integral data collection and management and the data querying and analysis of enormous and high-complexity data through the design of intuitive and effective web user interface and scientific data visualization using statistical graphs and thematic cartography. Furthermore, through the quantitative analysis of trend changed over long-term by the geo-spatial analysis with geo- processing, it's being used as a tool for provide a scientific basis for sustainable development and decision support in Saemangeum coast. Moreover, for the effective web-based information service, multi-level map cache, multi-layer architecture and geospatial database were implemented together.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.117-126
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• 2020

A maritime object detection system is an intelligent assistance system to maritime autonomous surface ship(MASS). It detects automatically floating debris, which has a clash risk with objects in the surrounding water and used to be checked by a captain with a naked eye, at a similar level of accuracy to the human check method. It is used to detect objects around a ship. In the past, they were detected with information gathered from radars or sonar devices. With the development of artificial intelligence technology, intelligent CCTV installed in a ship are used to detect various types of floating debris on the course of sailing. If the speed of processing video data slows down due to the various requirements and complexity of MASS, however, there is no guarantee for safety as well as smooth service support. Trying to solve this issue, this study conducted research on the minimization of computation volumes for video data and the increased speed of data processing to detect maritime objects. Unlike previous studies that used the Hough transform algorithm to find the horizon and secure the areas of interest for the concerned objects, the present study proposed a new method of optimizing a binarization algorithm and finding areas whose locations were similar to actual objects in order to improve the speed. A maritime object detection system was materialized based on deep learning CNN to demonstrate the usefulness of the proposed method and assess the performance of the algorithm. The proposed algorithm performed at a speed that was 4 times faster than the old method while keeping the detection accuracy of the old method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1083-1091
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• 2017

This paper describes a design of cryptographic processor supporting 224-bit elliptic curves over prime field defined by NIST. Scalar point multiplication that is a core arithmetic function in elliptic curve cryptography(ECC) was implemented by adopting the modified Montgomery ladder algorithm. In order to eliminate division operations that have high computational complexity, projective coordinate was used to implement point addition and point doubling operations, which uses addition, subtraction, multiplication and squaring operations over GF(p). The final result of the scalar point multiplication is converted to affine coordinate and the inverse operation is implemented using Fermat's little theorem. The ECC processor was verified by FPGA implementation using Virtex5 device. The ECC processor synthesized using a 0.18 um CMOS cell library occupies 2.7-Kbit RAM and 27,739 gate equivalents (GEs), and the estimated maximum clock frequency is 71 MHz. One scalar point multiplication takes 1,326,985 clock cycles resulting in the computation time of 18.7 msec at the maximum clock frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1254-1264
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• 2008

This paper suggests an extended memory polynomial model that improves accuracy in modeling memory effects of RF power amplifiers(PAs), and verifies effectiveness of the suggested method. The extended memory polynomial model includes cross-terms that are products of input terms that have different delay values to improve the limited accuracy of basic memory polynomial model that includes the diagonal terms of Volterra kernels. The complexity of the memoryless model, memory polynomial model, and the suggested model are compared. The extended memory polynomial model is represented with a matrix equation, and the Volterra kernels are extracted using least square method. In addition, the structure of digital predistorter and digital signal processing(DSP) algorithm based on the suggested model and indirect learning method are proposed to implement a digital predistortion linearization. To verify the suggested model, the predicted output of the model is compared with the measured output for a 10W GaN HEMT RF PA and 30 W LDMOS RF PA using 2.3 GHz WiBro input signal, and adjacent-channel power ratio(ACPR) performance with the proposed digital predistortion is measured. The proposed model increases model accuracy for the PAs, and improves the linearization performance by reducing ACPR.

• Journal of The Korean Association of Information Education
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• v.21 no.4
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• pp.451-462
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• 2017

This study selected 3D printing that is highly likely to be adopted in schools. This research was conducted in two stages: 1) proposing the learning activity framework for utilizing 3D printing in education, and 2) exploring the potential of integrating 3D printing in the school field. The '3D printing learning activity framework' proposed in this study includes four phases that are categorized according to the complexity of problem-solving processes and collaborative interaction: Step 1 as production through replication, Phase 2 as means of imaginary expression, Phase 3 as near problem-solving, and Phase 4 as expanded problem-solving. Next, we conducted the field study with 23 students in the 6th grade math class where they learned the various solid shapes and volumes through 3D printing-integrated activities. The lesson was considered as Phase 1, which is the production through replication. Overall, the results showed that the participants had positive perceptions about the efficacy of 3D printing activities, the quality of learning experience, and satisfaction. On the other hand, it was found that the usability of 3D printers and CAD program needs further improvement The contribution of this study can be found in the learning activity framework that can guide 3D printing activity design in school, and in the exploration of enhancing the connection between 3D printing activities and curricular relevance beyond simple interest toward a novel technology.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.89-97
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• 2015

This paper analyzes the duration of the construction document (CD) phase of 42 large public building projects delivered by the total solution service of Public Procurement Services in Korea from 2009 to 2014. The quality of construction documents significantly affects the quality of construction and facility management. Thus, securing appropriate time for the CD phase during project planning is important for the quality of a project. Currently, the duration of the CD phase is planned based on the construction costs of a project following a notice of the Ministry of Land, Infrastructure and Transport. However, our analysis results showed that the correlation between the actual duration of the CD phase and construction costs is very weak. The actual CD phase takes 1.33-1.79 times longer than the planned duration. The practitioners who were interviewed, were already aware that the correlation between the duration of the CD phase and the construction costs is weak. They identified the complexity of the project, the extent of the design changes, project type, client characteristics, and others as more influential factors on the CD phase than the construction costs. To improve the quality of CDs, a new guideline for determining an adequate CD phase duration should be studied and developed.