• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.725-734
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• 2006

As a sequel to Part 1, the performance characteristics of the cell averaging (CA), greatest of (GO), and smallest of (SO) constant false alarm rate (CFAR) processors in nonhomogeneous environment are obtained and compared when receiving antenna diversity is employed in the pseudonoise (PN) code acquisition of direct-sequence code division multiple access (DS/CDMA) systems. Unlike in homogeneous environment, the GO CFAR processor is observed to exhibit the best performance in nonhomogeneous environment, with the CA CFAR processor performing the second best.

• Korea-Australia Rheology Journal
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• v.16 no.4
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• pp.175-182
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• 2004

Colloidal coating solution was prepared to enhance the hydrophilic property of the film surface. Water and ethanol were used as the dispersion media and (glycidoxypropyl) trimethoxysilane (GPS) as a binder in the colloidal silica coatings. Ethylene diamine was added to the colloidal silica solution as the curing agent. The colloidal silica solution was regarded as a hard-sphere suspension model with low volume fraction of the silica particles. Rheological properties of the silica suspensions modified with GPS have been investigated as a function of pH and concentration. The acidic solution showed high viscosity change by fast hydrolysis reaction and adsorption of the organic binders on the surface of silica particles. However, the hydrolysis was slow at the basic condition and the binders combined with themselves by condensation. The viscosity change was smallest at pH 7. The viscosity increased with the curing time after adding ethylenediamine, and the increase of viscosity at low pH was higher than that at high pH. The hydrophilic properties of the coating film were investigated by the contact angle of water and film surface. The smallest contact angle was shown under the strong acidic condition of pH 2.

• Journal of the Korea Concrete Institute
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• v.12 no.4
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• pp.103-111
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• 2000

The influence of the improvement of grain shape of the coarse aggregate to the unit powder content of concrete and the fine aggregate ratio for the increase of the flowability and segregation resistance of high performance concrete was examined. According to the experimental results, flowability and compacting of concrete presents best states in the S/a which has the smallest 패야 ratio. The coarse aggregate after improvement of grain shape, that has changed from the 0.68 of spherical rate of disk shape to 0.73, led fine aggregate ratio to be down 6% (i.e from 47% to 41%). The improvement of grain shape of the coarse aggregate also led the lowest unit powder content to be down 60kg/㎥ (ie from 530kg/㎥ to 470kg/㎥). And approximate 10% of unit water content has been reduced as unit powder content was down. However, the compressive strength after the improvement of grain shape of the coarse aggregate decreased to 5% due to decrease of adhesiveness of the aggregate and cement paste.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.4
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• pp.47-52
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• 2011

Constant false alarm rate (CFAR) is an automatic detection algorithm for active sonar system. Among several CFAR algorithms, ordered statistics (OS) CFAR has the best performance over cell averaging (CA), smallest of (SO), greatest of (GO) algorithms at non-homogeneous environments. However, OS CFAR has the disadvantage of bad detection performance in multiple target conditions. We suggest an ordered statistics ratio (OSR) CFAR algorithm that is robust to multiple target environments. The proposed and conventional schemes are compared with computer simulations.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.10-14
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• 2016

Holographic data storage (HDS) features short access times, high storage capacities, and fast transfer rates since the data is recorded and read not by lines but by pages within a volume of holographic material. Furthermore, a single pixel can store more than 1 bit if it is multi-level. However, there is a problem of inter-symbol interference (ISI) between the adjacent symbols if the level difference between neighboring symbols is large. Hence, one should avoid side by side placement of the smallest level symbol and the largest level symbol in any direction. This paper proposes a 12/16 modulation code for 4-level holographic data storage, so that the largest symbol is 3 and the smallest symbol is 0, in order to reduce the ISI.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.248-254
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• 2005

The existing buffer management scheme is caused by with burstness characteristic of the TCP traffic and with only the transmission which is not loss it provides the smallest transmission rate guarantee where the GFR demands and a fair characteristic. In order to provide a high fair characteristic from the dissertation which it sees with the smallest transmission rate guarantee where the GFR demands it proposed the existing buffer algorithm which applies a Fuzzy mechanism in the existing buffer management technique. The proposed algorithm decides a packet disuse used by three parameters which are composed of tagging information, the buffer usage, and the load of VC. Simulation results shows that the fairness and goodput of the proposed algorithm were excellent where the size of MCR will become larger, from the switch the Double-EPD or the DFBA was visible a similar efficiency even from size change of the buffer. The algorithm which is proposed provides a good throughput and a fair characteristic.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.2
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• pp.223-237
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• 2015

This study is to compare the pattern making methods of men's jeans and to analyze sizes of parts while also evaluating the appearance and fit according to a 3D virtual garment simulation. Five types of patterns are selected for the analysis. For the appearance evaluation, the study conducted a virtual clothing simulation, created a perspective drawing, and applied Clothing pressure to each test outfit. First, according to the pattern comparisons, A and D had the shortest crotch length, while B had the longest; B had the narrowest crotch width, while C had the widest; C had the greatest waist circumference, and B had the smallest; C had the greatest knee and hem circumference, while E had the smallest. Second, according to the appearance evaluation, E pants had the highest rating overall for the waist, crotch, knee, and hem comfort; A pants had the highest rating for the yoke line end and placement; and C pants had the highest rating for the side seam line. According to the correlation analysis, ease of the waist, hips, hem and thighs were important factors (in that order) in determining the overall appearance of the jean pants.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.10
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• pp.11-16
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• 1999

In this study, Ultra-precision finishing system using micro abrasive film experimented using experimental variable film feed speed and grinding speed and structural steel(SM45C) with respect to 12~3{\mu}m$ micro abrasive film. the result are follows; (1) Experimental condition must setup dissimilar about each micro abrasive film. (2) To measurement deviation the smallest machined condition are 20mm/min in 12{\mu}m$, 5mm/min and 15mm/min in 9{\mu}m$ and 5{\mu}m$, 5mm/min in 3{\mu}m$ in film feed speed. (3) To measurement deviation the smallest machined condition are 180m/min in 12{\mu}m$, 84m/min in 9{\mu}m$, 56 and 84m/min in 5{\mu}m$, 104m/min in 3{\mu}m$ in grinding speed.

• Journal of the Korean Statistical Society
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• v.33 no.4
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• pp.411-433
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• 2004

The shrinkage preliminary test ridge regression estimators (SPTRRE) based on Wald (W), Likelihood Ratio (LR) and Lagrangian Multiplier (LM) tests for estimating the regression parameters of the multiple linear regression model with multivariate Student's t error distribution are considered in this paper. The quadratic biases and risks of the proposed estimators are compared under both null and alternative hypotheses. It is observed that there is conflict among the three estimators with respect to their risks because of certain inequalities that exist among the test statistics. In the neighborhood of the restriction, the SPTRRE based on LM test has the smallest risk followed by the estimators based on LR and W tests. However, the SPTRRE based on W test performs the best followed by the LR and LM based estimators when the parameters move away from the subspace of the restrictions. Some tables for the maximum and minimum guaranteed efficiency of the proposed estimators have been given, which allow us to determine the optimum level of significance corresponding to the optimum estimator among proposed estimators. It is evident that in the choice of the smallest significance level to yield the best estimator the SPTRRE based on Wald test dominates the other two estimators.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.85-88
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• 2006

This study investigated influence of fine aggregate types on fundamental properties of cement mortar. Test showed that concrete using lime stone crushed fine aggregate(L) exhibited the most favorable fluidity due to grain shape and particle distribution, and next was blending aggregate miting L and G, blending aggregate mixing L and N, granite crushed fine aggregate(G), natural fine aggregate(N) in an order. Concrete using N had the highest air content and L was the smallest value because of the effective filling performance by continuos particle distribution. Compressive, tensile and flexural strength of all concrete using L had the highest value due to the smallest value of air content. It is also found that concrete using L resulted in decrease of drying shrinkage length change ratio.