• Title/Summary/Keyword: Real Number

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Real-Estate Price Prediction in South Korea via Machine Learning Modeling (머신러닝 기법을 통한 대한민국 부동산 가격 변동 예측)

  • Nam, Sanghyun;Han, Taeho;Kim, Leeju;Lee, Eunji
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.6
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    • pp.15-20
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    • 2020
  • Recently, the real estate is of high interest. This is because real estate, which was considered only a residential environment in the past, is recognized as a stable investment target due to the ever-growing demand on it. In particular, in the case of the domestic market, despite the decrease in the number of people, the number of single-person households and the influx of people to large cities are accelerating, and real estate prices are rising sharply around the metropolitan area. Therefore, accurately predicting the prospects of the future real estate market becomes a very important issue not only for individual asset management but also for government policy establishment. In this paper, we developed a program to predict future real estate market prices by learning past real estate sales data using machine learning techniques. The data on the market price of real estate provided by the Korea Appraisal Board and the Ministry of Land, Infrastructure and Transport were used, and the average sales price forecast for 2022 by region is presented. The developed program is publicly available so that it could be used in various forms.

Logic circuit design for high-speed computing of dynamic response in real-time hybrid simulation using FPGA-based system

  • Igarashi, Akira
    • Smart Structures and Systems
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    • v.14 no.6
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    • pp.1131-1150
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    • 2014
  • One of the issues in extending the range of applicable problems of real-time hybrid simulation is the computation speed of the simulator when large-scale computational models with a large number of DOF are used. In this study, functionality of real-time dynamic simulation of MDOF systems is achieved by creating a logic circuit that performs the step-by-step numerical time integration of the equations of motion of the system. The designed logic circuit can be implemented to an FPGA-based system; FPGA (Field Programmable Gate Array) allows large-scale parallel computing by implementing a number of arithmetic operators within the device. The operator splitting method is used as the numerical time integration scheme. The logic circuit consists of blocks of circuits that perform numerical arithmetic operations that appear in the integration scheme, including addition and multiplication of floating-point numbers, registers to store the intermediate data, and data busses connecting these elements to transmit various information including the floating-point numerical data among them. Case study on several types of linear and nonlinear MDOF system models shows that use of resource sharing in logic synthesis is crucial for effective application of FPGA to real-time dynamic simulation of structural response with time step interval of 1 ms.

The Infinite Decimal Representation: Its Opaqueness and Transparency (무한소수 기호: 불투명성과 투명성)

  • Lee, Jihyun
    • Journal of Educational Research in Mathematics
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    • v.24 no.4
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    • pp.595-605
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    • 2014
  • Infinite decimals have an infinite number of digits, chosen arbitrary and independently, to the right side of the decimal point. Since infinite decimals are ambiguous numbers impossible to write them down completely, the infinite decimal representation accompanies unavoidable opaqueness. This article focused the transparent aspect of infinite decimal representation with respect to the completeness axiom of real numbers. Long before the formalization of real number concept in $19^{th}$ century, many mathematicians were able to deal with real numbers relying on this transparency of infinite decimal representations. This analysis will contribute to overcome the double discontinuity caused by the different conceptualizations of real numbers in school and academic mathematics.

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Development of Education and Training System for the Auto-Reclosing of Power Transmission System Using a Real Time Digital Simulator (실시간 계통시뮬레이터를 이용한 송전계통 자동재폐로 교육 및 훈련 시스템 개발)

  • Park, Jong-Chan;Yun, Sang-Yun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.1
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    • pp.1-9
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    • 2010
  • This paper summarizes an education and training system for the auto-reclosing of power transmission system using a real time digital simulator. The system is developed to understand the principle of reclosing and the sequence of automatic reclosing schemes, and practice the effects of reclosing actions to power system in real-time simulator. This study is concentrated into the following two parts. One is the development of real time education and training system of automatic reclosing schemes. For this, we use the RTDS(real time digital simulator) and the actual digital protective relay. The mathematical relay model of RTDS and the actual distance relay which is equipped automatic reclosing function are also used. The other is the user friendly interface between trainee and trainer. The various interface displays are used for user handing and result display. The conditions of automatic reclosing which is a number of reclosing, reclosing dead time, reset time, and so on, can be changed by the user interface panel. A number of scenario cases are reserved for the education and training. Through the test, we verified that the proposed system can be effectively used to accomplish the education and training of automatic reclosing.

Quantitative Detection of Salmonella typhimurium Contamination in Milk, Using Real-Time PCR

  • JUNG SUNG JE;KIM HYUN-JOONG;KIM HAE-YEONG
    • Journal of Microbiology and Biotechnology
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    • v.15 no.6
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    • pp.1353-1358
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    • 2005
  • A rapid and quantitative real-time PCR was developed to target the invasion A (invA) gene of Salmonella spp. We developed quantitative standard curves based on plasmids containing the invA gene. Based on these curves, we detected Salmonella spp. in artificially contaminated buffered peptone water (BPW) and milk samples. We were able to determine the invA gene copy number per ml of food samples, with the minimum detection limit of $4.1{\times}10^{3}$ copies/ml of BPW and $3.3{\times}10^{3}$ copies/ml of milk. When applied directly to detect and quantify Salmonella spp. in BPW and milk, the present real-time PCR assay was as sensitive as the plate count method; however, copy numbers were one to two logs higher than the colony-forming units obtained by the plate count methods. In the present work, the real-time PCR assay was shown to significantly reduce the total time necessary for the detection of Salmonella spp. in foods and to provide an important model for other foodborne pathogens.

Deterministic Multi-dimensional Task Scheduling Algorithms for Wearable Sensor Devices

  • Won, Jong-Jin;Kang, Cheol-Oh;Kim, Moon-Hyun;Cho, Moon-Haeng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.10
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    • pp.3423-3438
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    • 2014
  • In recent years, wearable sensor devices are reshaping the way people live, work, and play. A wearable sensor device is a computer that is subsumed into the personal space of the user, and is always on, and always accessible. Therefore, among the most salient aspects of a wearable sensor device should be a small form factor, long battery lifetime, and real-time characteristics. Thereby, sophisticated applications of a wearable sensor device use real-time operating systems to guarantee real-time deadlines. The deterministic multi-dimensional task scheduling algorithms are implemented on ARC (Actual Remote Control) with relatively limited hardware resources. ARC is a wearable wristwatch-type remote controller; it can also serve as a universal remote control, for various wearable sensor devices. In the proposed algorithms, there is no limit on the maximum number of task priorities, and the memory requirement can be dramatically reduced. Furthermore, regardless of the number of tasks, the complexity of the time and space of the proposed algorithms is O(1). A valuable contribution of this work is to guarantee real-time deadlines for wearable sensor devices.

The Effect of Real-time Traffic Information System Relieving Traffic Congestion

  • Kang, Ho Jun;Moon, Tae Nam;Lee, Kang Hyeok;Song, Young Do;Shin, Do Hyoung
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.652-653
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    • 2015
  • This study investigates the effect of real-time traffic information on the traffic flows in Korea. Recently, the development of smartphones has made it easier to use the route guidance service based on real-time traffic information. By the Big Data analysis in the study, it was found that the number of postings on the web community sites increased sharply in 2010 and 2011 when the smartphones spread widely. In the analysis of the traffic speeds by time, the average traffic speeds for morning and evening rush hours on weekdays from 2009 to 2014 of the 142 sections in the 6 national highways in Gyeonggi-do, Korea were used. From the results of the analysis, it was found that the percentage of the number of sections with the improved traffic flows increased greatly in 2012 compared to 2011. The findings of the study indicate the effect of the real-time traffic information on improving traffic flows.

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Forbidden Detour Number on Virtual Knot

  • Yoshiike, Shun;Ichihara, Kazuhiro
    • Kyungpook Mathematical Journal
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    • v.61 no.1
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    • pp.205-212
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    • 2021
  • We show that the forbidden detour move, essentially introduced by Kanenobu and Nelson, is an unknotting operation for virtual knots. Then we define the forbidden detour number of a virtual knot to be the minimal number of forbidden detour moves necessary to transform a diagram of the virtual knot into the trivial knot diagram. Some upper and lower bounds on the forbidden detour number are given in terms of the minimal number of real crossings or the coefficients of the affine index polynomial of the virtual knot.

Minimum-Power Scheduling of Real-Time Parallel Tasks based on Load Balancing for Frequency-Sharing Multicore Processors (주파수 공유형 멀티코어 프로세서를 위한 부하균등화에 기반한 실시간 병렬 작업들의 최소 전력 스케줄링)

  • Lee, Wan Yeon
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.6
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    • pp.177-184
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    • 2015
  • This paper proposes a minimum-power scheduling scheme of real-time parallel tasks while meeting deadlines of the real-time tasks on DVFS-enabled multicore processors. The proposed scheme first finds a floating number of processing cores to each task so that the computation load of all processing cores would be equalized. Next the scheme translates the found floating number of cores into a natural number of cores while maintaining the computation load of all cores unchanged, and allocates the translated natural number of cores to the execution of each task. The scheme is designed to minimize the power consumption of the frequency-sharing multicore processor operating with the same processing speed at an instant time. Evaluation shows that the scheme saves up to 38% power consumption of the previous method.

Study of the Real Number Field Extension Operand of Elliptic Curve Cryptography (타원곡선 암호의 실수체 확장 연산항에 관한 연구)

  • Woo, Chan-Il;Goo, Eun-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.9
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    • pp.5790-5795
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    • 2014
  • Elliptic curve cryptography (ECC) is an extremely important part of information protection systems because it has outstanding safety among public key encryption algorithms. On the other hand, as ECC cannot obtain accurate values using a real number field because of the slow calculation and errors from rounding off, studies of ECC have focused on a finite field. If ECC can be extended to the real number field, more diverse keys can be selected compared to ECC only based on a finite field. Accordingly, in this paper, a method for constructing a cryptographic system with a high degree of safety is proposed through the diversification of keys selected by the user based on the operant extension method instead of extracting keys only using integer values.