• Communications for Statistical Applications and Methods
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• v.20 no.3
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• pp.199-205
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• 2013

We employ sieve bootstraps for empirical likelihood tests in time series models because their null distributions are often vulnerable to the presence of serial dependence. We found a significant size refinement of the bootstrapped versions of a Lagrangian Multiplier type test statistic regardless of the bandwidth choice required by long-run variance estimations.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.209-221
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• 1994

Timers are commonly used in hardware design for time delays that are to be much longer than the system clock period. In this paper, we present a method by which we can synthesie a hardware containing timers that implement long time delays described in VHDL. Because, in general, timers require high hardware cost, they must be utilized as efficiently as possible. To solve this problem we define a graph model and propose an algorithm that uses the graph model to minimize number of timers. A preliminary experimental result show that the algorithm implements all required time delays using minimum number of timers.

• Ocean Systems Engineering
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• v.2 no.3
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• pp.173-187
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• 2012

In this study we investigate the reliability of a bar subjected to a random tensile load in presence of corrosion. We consider linear, quadratic and exponential models that connect the stress in the bar with the corrosion rate. Two probability densities are considered for the load, with attendant derivation of the time-dependant reliability. The design time of operation is determined utilizing the requirement that the reliability must not be less than the required value.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.43.3-43.3
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• 2018

We develop a model for broadband spectral energy distribution (SED) of Pulsar Wind Nebulae (PWNe). The model assumes that electrons/positrons in the pulsar wind are injected into and stochastically accelerated in the pulsar termination shock. We consider two scenarios: a stationary one-zone case and a time-evolving multi-zone case. In the latter scenario, flow properties in the PWNe (magnetic field, bulk speed) are modeled to vary in time and space. We apply the model to the broadband SED of the pulsar wind nebula 3C 58. From the modeling, we find that a broken power-law injection is required with the maximum electron energy of ~200 TeV.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.3
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• pp.77-83
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• 2000

This paper presents a new modular multiplier for Montgomery multiplication using iterative small carry save adder. The proposed multiplier is more flexible and suitable for long bit multiplication due to its scalable property according to design area and required computing time. We describe the word-based Montgomery algorithm and design architecture of the multiplier. Our analysis and simulation show that the proposed multiplier provides area/time tradeoffs in limited design area such as IC cards.

• Bulletin of the Korean Mathematical Society
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• v.59 no.2
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• pp.507-528
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• 2022

We propose a path integral method to construct a time stepwise local volatility for the stock index market under Dupire's model. Our method is focused on the pricing with the Monte Carlo Method (MCM). We solve the problem of randomness of MCM by applying numerical integration. We reconstruct this task as a matrix equation. Our method provides the analytic Jacobian and Hessian required by the nonlinear optimization solver, resulting in stable and fast calculations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.367-370
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• 2006

A GPS-based time synchronization technique employing a refined HW circuitry and SW algorithm is considered as fine time-management system for Low Earth Orbit (LEO) remote sensing satellites. By synchronizing the On-Board Time (OBT) within satellites to the GPS 1PPS, a very expensive, highly accurate on-board clock is not required to determine the precise on-board time management. Also, the satellite command generation in ground stations and postprocessing of earth observation data which a particular image is acquired. This paper analyses on-orbit verification of the existing satellite time sync architecture and presents a new time sync architecture, operation and relation between the OBT and the GPS time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.718-724
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• 2017

Considerable efforts have been made to expand the boundaries of domestic offshore plant industries, which have focused on the construction of the structures, to the engineering field. On the other hand, time domain analysis, which is one of the most important areas in designing floating offshore plants, relies mainly on the information given by foreign companies. As an early design of the Dynamic Positioning System (DPS) is mostly conducted by several specialized companies, domestic ship builders need to spend time and money to reflect the analysis into the hull shape design. This paper presents the framework required to analyze time domain performance of floating type offshore structures, which are equipped with DPS. To easily perform time domain analysis, framework generates the required input data for the solver, and is modularized to test the control algorithm and performance of a certain DPS. The effectiveness of the developed framework was verified by a simulation with a model ship and the total time for the entire analysis work was reduced by 50% or more.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.9-13
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• 2011

The Performance-based fire protection design required to construct super high-rise building is the active measure for the evaluation of fire risks and the establishment of fire protection systems on the basis of engineering analysis, which is more efficient and proper than existing prescriptive-based design. This study applied time-line analysis of RSET is required safe egress time and ASET is available safe egress time with the fire and evacuation simulation to analyze. The result of this study showed the sprinkler system increased ASET and fire detection and alarm system reduced RSET efficiently. Reduced evacuation time influences to secure the life safety. Also it is essential to maintain the fire suppression system and fire detection & alarm system properly. Database of fire movement and evacuation action program are useful for the performance-based design.

• Imaging Science in Dentistry
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• v.52 no.1
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• pp.93-101
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• 2022

Purpose: This study compared the effectiveness of complementary metal-oxide semiconductors (CMOS) and photostimulable phosphor (PSP) plates as intraoral imaging systems in terms of time efficacy, patient comfort, and subjective image quality assessment in real clinical settings. Materials and Methods: Fifty-eight patients (25 women and 33 men) were included. Patients were referred for a full-mouth radiological examination including 1 bitewing radiograph (left and right) and 8 periapical radiographs for each side (left maxilla/mandible and right maxilla/mandible). For each patient, 1 side of the dental arch was radiographed using a CMOS detector, whereas the other side was radiographed using a PSP detector, ensuring an equal number of left and right arches imaged by each detector. Clinical application time, comfort/pain, and subjective image quality were assessed for each detector. Continuous variables were summarized as mean±standard deviation. Differences between detectors were evaluated using repeated-measures analysis of variance. P<0.05 was accepted as significant. Results: The mean total time required for all imaging procedures with the CMOS detector was significantly lower than the mean total time required for imaging procedures with PSP (P<0.05). The overall mean patient comfort scores for the CMOS and PSP detectors were 4.57 and 4.48, respectively, without a statistically significant difference (P>0.05). The performance of both observers in subjectively assessing structures was significantly higher when using CMOS images than when using PSP images for all regions (P<0.05). Conclusion: The CMOS detector was found to be superior to the PSP detector in terms of clinical time efficacy and subjective image quality.