• ETRI Journal
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• v.36 no.3
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• pp.469-478
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• 2014

RSA signature algorithms using the Chinese remainder theorem (CRT-RSA) are approximately four-times faster than straightforward implementations of an RSA cryptosystem. However, the CRT-RSA is known to be vulnerable to fault attacks; even one execution of the algorithm is sufficient to reveal the secret keys. Over the past few years, several countermeasures against CRT-RSA fault attacks have tended to involve additional exponentiations or inversions, and in most cases, they are also vulnerable to new variants of fault attacks. In this paper, we review how Shamir's countermeasure can be broken by fault attacks and improve the countermeasure to prevent future fault attacks, with the added benefit of low additional costs. In our experiment, we use the side-channel analysis resistance framework system, a fault injection testing and verification system, which enables us to inject a fault into the right position, even to within $1{\mu}s$. We also explain how to find the exact timing of the target operation using an Atmega128 software board.

• The Journal of Fisheries Business Administration
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• v.47 no.4
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• pp.1-13
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• 2016

Fish mortality is the most important success factor in aquaculture management. To analyze the effect of mortality considering biological and economic condition is a important problem in land-based aquaculture. This study is aimed to analyze the effect of mortality for duration of cultivation in land-based aquaculture. This study builds the mathematical model that finds the value of decision variable to minimize cost that sums up the water pool usage cost, sorting cost, fingerling cost and feeding cost under critical standing corp constraint. The proposed mathematical model involves many aspects, both biological and economical: (1) number of fingerlings (2) timing and number of batch splitting event, based on (3) fish growth rate, (4) mortality, and (5) several farming expense. Numerical simulation model presented here in. The objective of numerical simulation is to provide for decision makers to analyse and comprehend the proposed model. When extensive biological and cost data become available, the proposed model can be widely applied to yield more accurate results.

• Journal of Mechanical Science and Technology
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• v.18 no.8
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• pp.1451-1460
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• 2004

A two-stroke Schnurle-type gasoline engine was modified to enable compression-ignition in both the port fuel injection and the in-cylinder direct injection. Using the engine, examinations of compression-ignition operation and engine performance tests were carried out. The amount of the residual gas and the in-cylinder mixture conditions were controlled by varying the valve angle rate of the exhaust valve (VAR) and the injection timing for direct injection conditions. It was found that the direct injection system is superior to the port injection system in terms of exhaust gas emissions and thermal efficiency, and that almost the same operational region of compression-ignition at medium speeds and loads was attained. Some interesting combustion characteristics, such as a shorter combustion period in higher engine speed conditions, and factors for the onset of compression-ignition were also examined.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.18-21
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• 2005

The impact of the interannual climatic variability on the vegetation sensitively appears in the timing of phenological events such as green-up, mature, and senescence. Therefore, an accurate and temporally high-resolution NDVI dataset will be required for analysis on the interannual variability of the climate-vegetation relationship. We constructed a daily 8km NDVI dataset over Eurasia based on the 8km tiled data of Pathfinder A VHRR Land (PAL) Global daily product. Cloud contamination was successfully reduced by Temporal Window Operation (TWO), which is a method to find optimized upper envelop line of the NDVI seasonal change. Based on the daily NDVI time series from 1982 to 2000, an accurate (daily) interannual change of the phenological events will be analyzed.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.733-740
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• 2005

In this paper, we propose an approach to transport layer mobility support leveraging the SCTP extension dubbed dynamic address reconfiguration in IPv6 networks. Timing issues related to the end-to-end address management, and a novel error recovery mechanism associated with a handover are discussed. The proposed error recovery mechanism is analyzed and compared to that of the plain SCTP to show that it reduces the handover latency and error recovery time.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.5
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• pp.30-40
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• 1992

Spark knock obstructs any improvement in the efficiency and performance of an engine. As the knock mechanism of spark ignition engine, the detonation and the autoignition theory have been offered. In this paper, the knock model was established, which was able to predict the onset of knock and knock timing of spark ignition engine by the basis of autoignition theory. This model was a function of engine speed and equivalent air-fuel ratio. When this established knock model was tested from 1000rpm to 3000rpm of engine speed data, maximum error was crank angle 2 degrees between measured and predicted knock time. And the main results were as follows by the experimental analysis of spark knock in spark ignition engine. 1) Knock frequency was increased as engine speed increased. 2) Knock amplitude was increased as mass of end gas increased. 3) Knock frequency was occured above minimum 18% mass fraction of end gas.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.2
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• pp.189-207
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• 1996

In this paper, a market share competition model for two firms with asymmetric conditions is considered with. In the model, the asymmetry between two firms is given by the difference of market shares In the existing market and the change of market share is supposed to be occurred only through pioneering a new market. Since the timing decision of market pioneering is based on the continuous time domain, a super game structure which has infinitely many numbers of subgames is employed for the modeling. In the course of equilibrium finding, we show that there exists no subgame-perfect pure strategy equilibrium In this game. So, we apply a mixed strategy concept and find a unique subgame-perfect equilibrium behavior strategy. As a result of equilibrium analysis, we know that the relative sizes of pioneering Incentives between two firms are varying with parameter conditions. However, the global speed of market pioneering is proven to be independent with the level of asymmetry between two firms.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.761-767
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• 1993

A precision planting system using computer controlled technology for mulching cultivation was developed and tested . The system consisting of a micro-computer, several optical fiber sensors and control actuators realized the mechanization of the precision planting operation. The film hole positions, existences of a seed on shutter were detected and the planting speed was measured. The shutter opening mechanism and a seed metering device driven by a stepping motor were controlled, automatically . The planting timing of the shutter opening mechanism were analyzed from a video camera motion analysis, theoretically. The results showed a sufficient accuracy of a seed planted into the center a film hole with a variety of planting speeded. The gravity point positions in film hole of seeds planted by the system just were within the area of +-5mm of the hole center when the hole diameter was 40mm.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.3
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• pp.337-344
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• 2000

In this paper, we define a Process Algebra ACSMR(Algebra of Communicating Shared Multiple Resources) for system specification and verification using multiple resources. ACSMR extends a concept of multiple resources in ACSR that is a branch of formal methods based on process algebra. We'll show that two specification and verification examples. One is the specification of system behavior in multiprocessor using EDF(Earliest-Deadline-First) which is a scheduling algorithm of a real-time system. The other is the specification of describing timing analysis and resources restriction in a super scalar processor using multiple ports registers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1219-1225
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• 2001

In this Paper we describe the design of synchronization algorithms for burst QPSK receiver, which are applicable to BWLL uplink. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we ufo Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.