• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.1
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• pp.52-60
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• 1999

This paper deals with a fault detection and isolation scheme for a DC motor driven centrifugal pump system. The emphasis is placed on the design and implementation of the residual generatorm, based on parity relation, that provides decision logic unit with residuals that will be further processed to detect and isolate three important faults in the system;brush fault, impeller fault, and the speed sensor fault. Two process faults are modelled as multiplicative type faults, while the sensor fault as an additive one. With multiplicative fault, the implementation of the residual generator needs the time varying transformation matrix that must be computed on-line. Typical implementation methods lack in generality because only a numerical approximation around the assumed fault levels is employed. In this paper, a new implementation method using well tranined neural network is proposed to improve the generality of the residual generator. Application results show that the fault detection and isolation scheme with the proposed residual generator effectively isolates three major faults in the centrifugal pump system even with a wide range of fault magnitude.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.798-801
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• 2010

This paper describes an efficient architecture for LDPC(Low-Density Parity Check) decoder, which supports three block lengths (648, 1,296, 1,944) of IEEE 802.11n standard. To minimize hardware complexity, the min-sum algorithm and block-serial layered structure are adopted in DFU(Decoding Function Unit) which is a main functional block in LDPC decoder. The optimized H-ROM structure for multi block lengths reduces the ROM size by 42% as compared to the conventional method. Also, pipelined memory read/write scheme for inter-layer DFU operations is proposed for an optimized operation of LDPC decoder.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.916-927
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• 2010

In this paper, we analyze the performance of the parity cache enabled RAID level-5 via the simulation. This RAID system consists of the DDR memory-based storage devices. To do this, we develop the simulation model and suggest the basic performance analysis data which we want to get via the simulation. And we implement the simulator based on the simulation model and execute the simulator. From the result of the simulation, we expect that the parity cache enabled RAID level-5 configured by the DDR memory based storage devices has the positive effectiveness to the enhancing of the storage system performance if the storage access patterns of applications are tuned.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3458-3481
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• 2021

Existing methods for blind identification of linear block codes without a candidate set are mainly built on the Gauss elimination process. However, the fault tolerance will fall short when the intercepted bit error rate (BER) is too high. To address this issue, we apply the reverse algebra approach and propose a novel "two-step-screening" algorithm by solving the linear error equations on the binary Galois field, or GF(2). In the first step, a recursive matrix partition is implemented to solve the system linear error equations where the coefficient matrix is constructed by the full codewords which come from the intercepted noisy bitstream. This process is repeated to derive all those possible parity-checks. In the second step, a check matrix constructed by the intercepted codewords is applied to find the correct parity-checks out of all possible parity-checks solutions. This novel "two-step-screening" algorithm can be used in different codes like Hamming codes, BCH codes, LDPC codes, and quasi-cyclic LDPC codes. The simulation results have shown that it can highly improve the fault tolerance ability compared to the existing Gauss elimination process-based algorithms.

• International Area Studies Review
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• v.13 no.1
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• pp.103-122
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• 2009

The paper is basically designed to investigate any existence of co-movement among foreign exchange market, goods market, and monetary market implemented by relative PPP and interest rate parity. And, rational expectation and GARCH-M model are employed for an empirical application. The result revealed that since the co-movement among the markets is hardly found, an efficiency of foreign exchange market is independent from any shocks from the goods market and the monetary market. Whereas, the exchange rate is strongly effected by a real interest rate parity. To this end, the real interest rate should be a key policy instrument to stabilize the foreign exchange market.

• Korea Trade Review
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• v.47 no.5
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• pp.75-93
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• 2022

Purchasing Power Parity (hereafter, PPP) means the purchasing power of two currencies is the same when one is converted into the other one. According to previous studies on PPP, as the volatility of the real exchange rate is smaller, PPP may be more likely to hold. Since New Zealand adopted the inflation targeting policy in December 1989, many countries started to adopt it as their monetary policy frame. Previous studies on inflation targeting found that inflation targeting policy has positive effects on not only achieving price stability but also reducing the volatility of nominal/ real exchange rates. Therefore, in this study, I explored whether inflation targeting policy has positive effects on purchasing power parity subject to 19 OECD countries, applying an Exponential Smooth Transition Autoregressive (ESTAR) model during the sample periods, from 1974:Q1 to 2019:Q4. Based on the ESTAR estimate results, I found limited favorable evidence of PPP for only two countries- England and Switzerland- among 9 inflation targeters, compared to non-inflation targeters, and also I found that favorable evidence of PPP only for these two countries among 9 inflation targeters during post-inflation targeting, but not during pre-inflation targeting. These findings imply that the positive effects of inflation targeting on PPP may be questionable unlike Ding and Kim (2012) and Kim (2014)'s study.

• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.205-229
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• 2004

The deviation from put-call parity condition may affect market prices since it provides an opportunity of arbitrage to many participants. This study uses the KOSPI200 index data and examines the interdependence among spot, futures, and options contracts by examining whether the deviations from the parity have significant roles in price formation. Whenever the parity condition is violated, the deviation tends to affect the prices significantly in most markets. The results show that positive values of deviation are associated with the fall of the prices in the spot and put option contracts and the rise of the call option premiums, thus decreasing the deviations. Also, the decreasing impact of deviations lasts for at Beast an hour in most markets. Futures prices, however, do not show clear relations with the deviations, which suggests the possibility that futures markets lead other markets.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.23-27
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• 2013

This study was carried out to investigate the influence of artificial insemination (AI) failure in 1,619 Korean native cows at Gangwon East area, Korea. The average AI failure rate was 37.02% in the cows and the highest rate was 40.85% in Yangyang-city. Based on the parity in the cows, the AI failure rate was 49.14% and 29.91% in the first and fifth parity cows, respectively. Whereas cows until fifth parity were decreased in AI failure, cows with sixth or more parity showed an upturning AI failure trends with the increasing of parity number. AI failure rate incidence according to the rump fat thickness measured by ultrasound was 28.9% and 33.4% at 5 mm to 10 mm and over than 15 mm, respectively. There was a positive correlation (0.2186) between AI failure rate of mother and that of their offspring cows. That is, offspring of dams with high AI failure rate showed also higher AI failure than those of dams having lower AI failure rate. In conclusion, these results indicate that the AI failure rate was closely related to the rump fat thickness, parity number, and conception rate of mother cows. In addition, these results might strengthen the basis to improve the reproductive performance in Korean native cows.

• The Korean Journal of Financial Management
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• v.3 no.1
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• pp.99-120
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• 1987

• Clinical and Experimental Reproductive Medicine
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• v.2 no.2
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• pp.37-40
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• 1975