• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.337-342
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• 2002

A new apparatus called the EFA (Erosion Function Apparatus) has been built and tested to measure the erodibility of fine-grained soils. The EFA is a simple test to predict the erosion rate of fine-grained soils along with the corresponding velocity and shear stress. In addition, it is advantageous in predicting the scour rate for actual soil samples from bridge sites. The plot of erosion rate versus shear stress is the result of an EFA test. It Indicates the critical shear stress at which erosion starts and the rate of erosion beyond that shear stress. In order to measure the erodibilities of various soils, 14 Shelby Tube soil samples are collected from the actual bridge sites and tested using the EFA. The results of the EFA tests which are the relationships between erosion rates and shear stresses are presented in this paper and research continues to develop the correlation between the erosion function and the soil properties.

• Journal of Pharmaceutical Investigation
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• v.4 no.4
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• pp.26-37
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• 1974

Having measured physical canstant and dissolution rate of prednisolone powder, and tablets, also particle size, particle number of powder disintegration, hardness, friability of prednisolone tablets and having also compared it's interrelationship. We obtained the results as following. 1) Dissolution rate of prednisolone powder was determinded cube root rule and: the slope $({\alpha})$ was $3.1915{\times}10^{-2}$. 2) The tablet used in this study was fourteen kind of prednisolone tablets, two kinds of which were not conformity with prednisolone dissolution rate test of U.S.P. XVIII, but the rest of them were conformity with the same test (t60% was 4.3minute in average) 3) There was no significant interrelationship between disintegration, hardness, friability and dissolution rate of prednisolone tablet used in this study but we recognized the disintegration time was greatly influenced by the dissolution rate.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.154-159
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• 1998

In order to assess the susceptibility of the environmentally assisted cracking(EAC) on SA508 Cl.3 steel in primary water condition, potential step test and slow strain rate test(SSRT) were conducted in a simulated crack tip condition. In this test, anodic dissolution was dominant in the crack tip environments. Proposed simple dissolution model is a modification of Hishida's anodic dissolution model at the plastic zone. One can predict actual crack growth rate with the smooth specimen through this model.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.293-303
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• 1999

When test outcomes of units are dichotomous and he infection rate is small group testing is more efficient that noe-to-one testing in estimating the true p and classifying units as infected or not. In this paper two-sided hypothesis testing and confidence intervals are derived based on the UMP(uniformly most powerful) unbiased test. The UMP unbiased approach is compared with Thompson's and Bhattacharyya et al.'s approaches by computing the length of confidence intervals and capture probabilities and shown to have a number of desirable properties. Unequal allocation one of advantages of the proposed approach is also mentioned.

• The KIPS Transactions:PartA
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• v.16A no.2
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• pp.79-88
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• 2009

In boundary scan architecture, test stimuli are shifted in one at a time and applied to the on-chip system logic. The test results are captured into the BSR and are examined by subsequent shifting. In this paper, we developed a continuous capture test architecture and test procedure using TPG based on boundary scan is used to performance test. In this architecture, test patterns of TPG are applied to CUT with system clock rate, and response of CUT is continuously captured by CBSR(Continuous Capture Boundary Scan Register) at the same rate and the captured results is shifted to TDO at the same rate. The suggested a continuous capture test architecture and test procedure is simulated by Altera Max+Plus 10.0. The simulation results shows the accurate operation and effectiveness of the proposed test architecture and procedure.

• Journal of the Korean Data and Information Science Society
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• v.20 no.4
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• pp.655-660
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• 2009

As the global economic crisis, the Korean foreign exchange market appears unstable with large fluctuations in exchange rate. Inevitably, there is growing attention on price variables such as exchange rate and interest rates and also on corelation between the factors. This is an empirical study on the causality of fluctuation between exchange rate and interest rate in the Korean market under global economic crisis. The fluctuations in won/dollar exchange rate and call rate are described and followed by analysis of lead-lag relationship between the two variables using Cross-correlation function and Granger causality test.

• Journal of KSNVE
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• v.9 no.1
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• pp.85-96
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• 1999

For ASME Code pumps in nuclear power plants, inservice test is required to assess the operational readiness in accordance with ASME code and related regulations. The objective of this study therefore, is to develop the technical background of the degradation of pump performances and conditions due to low flow rate operation. In addition. the detection techniques of pump operating conditions are to be developed to enhance the safety and economy of nuclear power plants. A test loop consisted of pump, motor. water tank, flow rate measurements and piping system with flow control devices was established for this study. Two typical pumps, 1-stage volute pump and 3-stage turbine pump, were selected and the test was performed upon two major point of views ; i.e., pump discharge pressure pulsations analysis and pump vibration spectrum analysis. From the test results, it is concluded that (1) the pump vibration affected by the natural frequency of operating pump is significant in the low frequency zone (around 1 Hz) : the vibration amplitude. especially. is an important factor during low flow rate operation. and shall be monitored to ensure that it is within the limit of ASME OM code Part 6, (2) the vibration frequency and pump discharge pressure are affected by vane pass frequency and running speed, (3) the wave phenomena due to the compressiblity of water is anticipated during low flow rate operation. and the pump system shall be designed to prevent it and. finally, (4) the technical background of the degradation of pump performances and conditions due to low flow rate operation is provided.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.25-32
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• 1996

The Bioconcentration factor(BCF) is used as an important criterion in the risk assessment of environmental contaminants. Also it can be used as indicator of biomagnification of environmentally hazardous chemicals through food-chain as well as a tool for ranking the bioconcentration potential of the chemicals in the environment. This paper reports the measured BCF value on carbofuran in Carassius auratus(goldfish), under steady state, and examined corelation between the BCF value and the depuration rate constant. Carassius auratus(goldfish) was chosen as test organism and test periods were 1-day, 3-day and 5-day. Experimental concentrations were 0.05, 0.10 and 0.50 ppm. Carbofuran in fish tissue and in test water was extracted with n-hexane and acetonitril. GC-ECD was used to detect and quantitate carbofuran. The depuration rate of carbofuran from the whole body of goldfish is determined over the 24-h period after treatment. The obtained results were as follows: 1. It was possible to determine short term BCFs of carbofuran through relatively simple procedure in environmental concentrations. 2. $BCF_1$ of carbofuran in concentration of 0.05, 0.10 and 0.50 ppm were 1.66, 1.64 0.61, $BCF_3$ were 2.08, 2.14, 0.66 and $BCF_5$ were 2.21, 2.57, 0.86, respectively. 3. Carbofuran concentration in fish extract was increased as increasing test concentration and prolonging test period, but $BCF_s$ in concentration of 0.50 ppm was greately decreased. 4. Determined deputation rate constants of carbofuran in concentration of 0.05, 0.10, 0.50 ppm were 0.076, 0.082 and 0.089, respectively. 5. It is considered that great decrease of $BCF_s$ in concentration of 0.50 ppm is due to high water solubility and stability of carbofuran in testwater. 6. It is suggested that low BCF of carbofuran is due to its relatively high water solubility and depuration rate, compared to BPMC, carbaryl and chlorothalonil.

• Corrosion Science and Technology
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• v.21 no.3
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• pp.230-241
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• 2022

Austenitic stainless steel has been widely used because of its good corrosion resistance and mechanical properties. However, intergranular corrosion can occur if the alloy is welded or aged. The objective of this study was to determine intergranular corrosion behaviors of austenitic medium carbon (0.05 wt%) and low carbon (0.02 wt%) stainless steel aged at several conditions. Alloys were evaluated according to ASTM A262 Practice A, ISO 12732 DL-EPR (double loop-electrochemical potentiokinetic reactivation) test, and ASTM A262 Practice C. The degree of sensitization and intergranular corrosion rate were obtained. The relationship between the degree of sensitization and the intergranular corrosion rate showed a very large fluctuation. Such behavior might be related to whether two-dimension tests or three-dimension tests were performed. On the other hand, regardless of carbon content of alloys, when the intergranular corrosion rate increased, the degree of sensitization also increased. However, the DL-EPR test showed a higher sensitivity than the Huey test for differentiating the intergranular corrosion property at a low intergranular corrosion rate, while the Huey test had a higher sensitivity than the DL-EPR test for distinguishing the intergranular corrosion property at a high intergranular corrosion rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.201-206
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• 2007

In this paper, we propose the efficient low power test methodology of NoC(Network-on chip) for the test of core-based systems that use this platform. To reduce the power consumption of transferring data through router channel, the scan vectors are partitioned into flits by channel width. The don't cares in unspecified scan vectors are mapped to binary values to minimize the switching rate between flits. Experimental results for full-scanned versions of ISCAS 89 benchmark circuits show that the proposed method leads to about 35% reduction in test power.