• Journal of the Korean Mathematical Society
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• v.59 no.3
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• pp.621-634
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• 2022

The scaled inverse of a nonzero element a(x) ∈ ℤ[x]/f(x), where f(x) is an irreducible polynomial over ℤ, is the element b(x) ∈ ℤ[x]/f(x) such that a(x)b(x) = c (mod f(x)) for the smallest possible positive integer scale c. In this paper, we investigate the scaled inverse of (xⁱ - x^j) modulo cyclotomic polynomial of the form Φ_p^s (x) or Φ_p^sq^t (x), where p, q are primes with p < q and s, t are positive integers. Our main results are that the coefficient size of the scaled inverse of (xⁱ - x^j) is bounded by p - 1 with the scale p modulo Φ_p^s (x), and is bounded by q - 1 with the scale not greater than q modulo Φ_p^sq^t (x). Previously, the analogous result on cyclotomic polynomials of the form Φ_2ⁿ (x) gave rise to many lattice-based cryptosystems, especially, zero-knowledge proofs. Our result provides more flexible choice of cyclotomic polynomials in such cryptosystems. Along the way of proving the theorems, we also prove several properties of {x^k}_k∈ℤ in ℤ[x]/Φ_pq(x) which might be of independent interest.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.713-718
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• 2016

Predicting precise specifications of differential mixed-signal circuits is a difficult problem, because analytically derived correlation between process variations and conventional specifications exhibits the limited prediction accuracy due to the phase unbalance, for most self-tests. This paper proposes an efficient prediction technique to provide accurate specifications of differential mixed-signal circuits in a system-on-chip (SoC) based on a nonlinear statistical nonlinear regression technique. A spectrally pure sinusoidal signal is applied to a differential DUT, and its output is fed into another differential DUT through a weighting circuitry in the loopback configuration. The weighting circuitry, which is employed from the previous work [3], efficiently produces different weights on the harmonics of the loopback responses, i.e., the signatures. The correlation models, which map the signatures to the conventional specifications, are built based on the statistical nonlinear regression technique, in order to predict accurate nonlinearities of individual DUTs. In production testing, once the efficient signatures are measured, and plugged into the obtained correlation models, the harmonic coefficients of DUTs are readily identified. This work provides a practical test solution to overcome the serious test issue of differential mixed-signal circuits; the low accuracy of analytically derived model is much lower by the errors from the unbalance. Hardware measurement results showed less than 1.0 dB of the prediction error, validating that this approach can be used as production test.

• Journal of The Korean Digital Architecture Interior Association
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• v.13 no.4
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• pp.77-86
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• 2013

Uigwe is official reports of the Joseon dynasty. They published from early Joseon but remain from 17C. We can search many hidden informations in them. Ga-Jungjagak (temporary T-shaped house) is one of them. It is unique architecture of the Joseon dynasty but it doesn't exist now at all. We can see many drawings describing Ga-Jungjagak (temporary T-shaped house) located next to Jungjagak in Uigwe. Jungjagak (T-shaped house) was built in royal tombs for sacrifice. Ga-Jungjagak was built in royal tombs for sacrifice as Jungjagak but existed temporarily. In this study, I want to find the process of norms Ga-Jungjagak in old records, official reports and annals of the Joseon Dynasty. Results are as follows: Ga-Jungjagak is the sacrifice space for queens in royal tombs. It is need to avoid sacrifice of delight and sorrow at the same time. They sacrifice to represent sorrow after the death of kings and queens for three years. After three year, they sacrifice to represent delight for kings and queens became ancestral gods. Ga-Jungjagak was destroyed three years later to combined sacrifices. The shape of Ga-Jungjagak is similar to Jungjagak in the same tomb. But dimensions of Ga-Jungjagak are equal or smaller than Jungjagak and decorations are abstemious.

• Smart Structures and Systems
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• v.17 no.6
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• pp.935-956
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• 2016

With the help of advanced image acquisition and processing technology, the vision-based measurement methods have been broadly applied to implement the structural monitoring and condition identification of civil engineering structures. Many noncontact approaches enabled by different digital image processing algorithms are developed to overcome the problems in conventional structural dynamic displacement measurement. This paper presents three kinds of image processing algorithms for structural dynamic displacement measurement, i.e., the grayscale pattern matching (GPM) algorithm, the color pattern matching (CPM) algorithm, and the mean shift tracking (MST) algorithm. A vision-based system programmed with the three image processing algorithms is developed for multi-point structural dynamic displacement measurement. The dynamic displacement time histories of multiple vision points are simultaneously measured by the vision-based system and the magnetostrictive displacement sensor (MDS) during the laboratory shaking table tests of a three-story steel frame model. The comparative analysis results indicate that the developed vision-based system exhibits excellent performance in structural dynamic displacement measurement by use of the three different image processing algorithms. The field application experiments are also carried out on an arch bridge for the measurement of displacement influence lines during the loading tests to validate the effectiveness of the vision-based system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1796-1802
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• 2011

In this paper, the radio propagation path loss prediction simulator in tunnel was developed. It used a image theory method for analysing precise radio propagation path. And it can predict radio propagation path loss in straight and curved tunnels. The simulator can plot realtime radio propagation paths using various parameters which was input by user. And it can simulate from changing transmitter and receiver positions. The predicted path loss of simulator was compared with the measurements in Chunhyun tunnel and confirmed the validity.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.517-524
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• 2017

Cyber security is an important issue in the field of nuclear engineering because nuclear facilities use digital equipment and digital systems that can lead to serious hazards in the event of an accident. Regulatory agencies worldwide have announced guidelines for cyber security related to nuclear issues, including U.S. NRC Regulatory Guide 5.71. It is important to evaluate cyber security risk in accordance with these regulatory guides. In this study, we propose a cyber security risk evaluation model for nuclear instrumentation and control systems using a Bayesian network and event trees. As it is difficult to perform penetration tests on the systems, the evaluation model can inform research on cyber threats to cyber security systems for nuclear facilities through the use of prior and posterior information and backpropagation calculations. Furthermore, we suggest a methodology for the application of analytical results from the Bayesian network model to an event tree model, which is a probabilistic safety assessment method. The proposed method will provide insight into safety and cyber security risks.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.11
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• pp.544-547
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• 2006

In this paper, we present a temperature-controlled system for MEMS electrical resistance heaters without a temperature sensor. To rapidly control the heater temperature, the microheater system developed consists of a power supply, power amplifier, digital ${\underline{P}}roportional-{\underline{I}}ntegral-{\underline{D}}ifferential$ (PID) controller, and a quarter bridge circuit with the microheater and three resistors are nominally balanced. The microheaters are calibrated inside a convection oven to obtain the temperature coefficient with a linear or quadratic fit. A voltage amplifier applies the supply voltage proportional to the control signal from the PID controller. Small changes in heater resistance generate a finite voltage across the quarter bridge circuit, which is fed back to the PID controller to compare with the set-point and to generate the control signal. Two MEMS microheaters are used for evaluating the developed control system - a NiCr serpentine microheater for a preconcentrator and a Nickel microheater for ${\underline{P}}olymerase\;{\underline{C}}hain\;{\underline{R}}eaction$ (PCR) chip.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.857-864
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• 2002

Channel coding is one of the most important things to improve digital communications. In this paper, we analyze the performance of turbo code with block interleaver using hopping algorithm (i. e., non-linear interleaver) for high speed multi-media service. The input and output of conventional block interleaver is achieved by the order of column and row, but hoping algorithm is achieved by hopping the column and row that increase the minimum distance and average distance between the nearest data dually. To verify and compare the performance of an proposed method the computer simulation have been performed using turbo code in gaussian channel environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.440-443
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• 2002

Present1y the X-Ray diagnosis system is a real condition that is changing by digital ways in it's existent analog ways. This digital radiation detector is divided by the direct method and the indirect method. The indirect method of applied voltage has special qualities that the resolution is low than direct method by diffusion effect that happens. The conversion process ( radiation${\rightarrow}$visible ray${\rightarrow}$electrical signal of two times, has shortcomings that the energy conversion efficiency of electrical signal is low. The direct method has shortcomings that need strong electric fie1d to detect electrical signal efficiently. This research achieved to develop digital detector of the Hybrid method that have form that mixes two ways to supplement shortcoming of direct. indirect method. A studied electrical characteristic by Iodine's Mixture ratio change is added to selenium in the detector which has a multi-layer structure (Oxybromide + a-Se). There are 8 kinds of Manufactured compositions to amorphous selenium Iodine each 30ppm, 100ppm, 200 ppm, 300ppm, 400ppm, 500ppm, 600ppm, 700ppm by a doped photoconductor through a vacuum thermal evaporation method. The phosphor layer is consisted of Oxybromide ($BrO_2$) which uses optical adhesives multi-layer structure. The manufactured compositions calculates and compares Net Charge and signal to noise ratio measuring Photocurrent about Darkcurrent and X-ray. When doped Iodine Mixture ratio is 500ppm to the multi-layer structure (Oxybromide + a-Se), applied voltage of $3V/{\mu}m$, leakage current of compositions $2.61nA/cm^2$ and net charge value by 764pC/$cm^2$/mR then the best result appeared.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.1-8
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• 2008

The concept of growing degree-days (GDD) is widely accepted as a tool to relate plant growth, development, and maturity to temperature. Information on GDD can be used to predict the yield and quality of several crops, flowering date of fruit trees, and insect activity related to agriculture and forestry. When GDD is expressed on a spatial basis, it helps identify the limits of geographical areas suitable for production of various crops and to evaluate areas agriculturally suitable for new or nonnative plants. The national digital climate maps (NDCM, the fine resolution, gridded climate data for climatological normal years) are not provided on a daily basis but on a monthly basis, prohibiting GDD calculation. We applied a widely used GDD estimation method based on monthly data to a part of the NDCM (for Hapcheon County) to produce the spatial GDD data for each month with three different base temperatures (0, 5, and $10^{\circ}C$). Synthetically generated daily temperatures from the NCDM were used to calculate GDD over the same area and the deviations were calculated for each month. The monthly-data based GDD was close to the reference GDD using daily data only for the case of base temperature $0^{\circ}C$. There was a consistent overestimation in GDD with other base temperatures. Hence, we estimated spatial GDD with base temperature $0^{\circ}C$ over the entire nation for the current (1971-2000, observed) and three future (2011-2040, 2041-2070, and 2071-2100, predicted) climatological normal years. Our estimation indicates that the annual GDD in Korea may increase by 38% in 2071-2100 compared with that in 1971-2000.