• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.5
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• pp.431-437
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• 2000

Standard Test Block(STB) for UT(Ultrasonic Testing) is a block approved by authoritative for material, shape and quality. STB is used for characteristic tests, sensitivity calibration and control of the time base range of UT inspection devices. The material, size and chemical components of STB should be strictly controled to meet the related standards such as ASTM and JIS because it has an effect upon sensitivity, resolution and reproductivity of UT. The STBs which are not approved are sometimes used because the qualified STBs are very expensive. So, the purpose of this study is to survey the characteristics, quality and usability of Non-Standardized Test Blocks. Non-Standardized Test Blocks did not meet the standard requirements in size or chemical components, and ultrasonic characteristics. Therefore if the Non-Standardized Test Blocks are used without being tested, it's likely to cause errors in detecting the location and measuring the size of the defects.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.1
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• pp.19-29
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• 2019

Recent earthquakes in Korea caused some damages to stone pagodas and thereby awakened the importance of earthquake preparedness. Korean stone pagodas which have been built with very creative style of material use and construction method are worthy of world heritage. Each stone pagoda consists of three parts: top; body; and base. However each tower is uniquely defined by its own features, which makes it more difficult to generalize the seismic assessment method for stone pagodas. This study has focused on qualitative preliminary evaluation of stone pagodas that enables us to compare the relative seismic performance across major aspects among many various Korean pagodas. Specifically an analytical model for multi-block stone pagodas is to be proposed upon the investigation of structural characteristics of stone pagoda and their dynamic behavior. A strategy for seismic evaluation of heritage stone pagodas is to be established and major evaluation factors appropriate for the qualitative evaluation are identified. The evaluation factors for overall seismic resisting behavior of stone pagodas are selected based on the dynamic motions of a rigid block and its limit state. Numerical simulation analysis using discrete element method is performed to analyze the sensitivity of each factor to earthquake and discuss some effects on seismic performance.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1589-1598
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• 1999

Conventional MSE or PSNR based methods for objective picture quality assessment of moving picture coder are not well correlated with subjective human evaluation. In recent years, the design of better objective quality assessment has attracted much intention and several picture quality metrics based on the properties of Human Visual System has been proposed. This paper proposes new metric which is appropriate for objective picture quality assessment of block based moving picture coder by considering frequency sensitivity, inter-intra channel masking and several distortion artifacts caused by block based coding. The experimental results show that the proposed method is good correlated with subjective assessment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.11
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• pp.786-792
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• 2004

A wavelet based ECG data compression has become an attractive and efficient method in many mobile tele-cardiology applications. But large data size required for high compression performance leads a serious delay. In this paper, new wavelet compression method with minimum delay is proposed. It is based on deciding the type and compression ratio(CR) of block organically according to the standard deviation of input ECG data with minimum block size. Compression performances of the proposed algorithm for different MIT ECG Records were analyzed comparing other ECG compression algorithm. In addition to the processing delay measurement, compression efficiency and reconstruction sensitivity to error were also evaluated via random noise simulation models. The results show that the proposed algorithm has both lower PRD than other algorithm on same CR and minimum time in the data acquisition, processing and transmission.

• Smart Structures and Systems
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• v.13 no.6
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• pp.959-974
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• 2014

Hand-Arm Vibration Syndrome (HAVS) is a group of diseases caused by exposure of the hands to vibration while operating the hand held power tools such as road breaker, drilling machine, demolition hammer in construction works. In this paper, area-changed capacitive micro-accelerometer is designed to measure the vibration exposure on worker's hand when operating a drilling machine on various blocks such as clay block, paver block and solid cement block. The design process includes mathematical modelling of micro-accelerometer and simulations are done using INTELLISUITE 8.6. Experimental results are taken for various blocks surfaces using conventional and micro-accelerometer. Comparisons show that usage of area-changed micro-accelerometer for Hand-arm vibration monitoring provides better sensitivity, which in turn reduces the risk of HAVS in workers.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.5
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• pp.424-431
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• 2002

This paper proposes a new quantitative image assessment model which is essential to verify the performance of block-based DCT coding. The proposed model considers not only global distortions such as frequency sensitivity and channel masking using HVS based visual model, but also distortions including several local distortions caused by block-based coding.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.185-189
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• 1987

An analysis and design of large-scale linear multivariable systems often requires to be block triangularized form for good sensitivity of the systems when their poles and zeros are varied. But the decomposition algorithms presented up to now need a procedure of permutation, rescaling and a solution of nonlinear algebraic equations, which are usually burden. To avoid these problem, in this paper we develop a newly alternative block triangular decomposition algorithm which used the generalized matrix sign function on the Z-plane. Also, the decomposition algorithm demonstrated using the fifth order linear model of a distillation tower system.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.711-712
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• 2005

• Environmental Mutagens and Carcinogens
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• v.10 no.2
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• pp.93-106
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• 1990

The Drosophila temperature-sensitive mutant shibire (shi) is paralyzed at restrictive temperature by a reversible block in synaptic transmission. To explore the functional relationship among shi gene products, viability and temperature-sensitive paralytic behavior were quantitaively analyzed for four shi alleles, shi$^{ts1}$, shi$^{ts2}$, shi$^{ts4}$, and shi$^{ST139}$, and their heteroallelic combinations. The hemizygous combination of shi alleles over deficiency was not completely lethal. shi$^{ts2}$ exhibited distinctively higher viability than other alleles. A novel behavior, bang sensitivity, was also found in shi/Df(1). This bang-sensitive paralytic behavior was compared with that of the typical bang-sensitive mutant flies. Heterozygotes, shi/+, are more severe in temperature sensitivity than deficiency hemizygotes, Df(1)/+. Heteroallelic combinations of shi were less sensitive to high temperature than homozygotes. Among all allelic combinations, shi$^{ts2}$/shi$^{ts4}$ showed an unexpected extreme reduction in temperature sensitivity. The results of allelic interactions among 4 shi alleles suggest that the shi mutations examined behave as antimorphic alleles and that the gene product of shi are likely to function in multimeric forms.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.2
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• pp.66-72
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• 2013

Fine Needle Aspiration Biopsy Cytology (FNABC), which is known as the most accurate and cost-effective method for diagnosis of the thyroid nodule, may still result in indeterminate cases that are cellular paucity and show minor nuclear atypia. However, most cases are associated with suspicion of papillary thyroid carcinoma (PTC). A B-type Raf kinase (BRAF) mutation was found in about half of PTCs which is currently helping us to differentiate malignancies from benign lesions. Cases studied included 46 histological, confirmed PTC cases. FNABC 102 cell paucity and 74 atypia benign cases were previously diagnosed as suspicious of PTC using cytologic examination. These cases were analyzed for BRAF mutation by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with a new restriction enzyme. In this study, the sensitivity and specificity were calculated and, BRAF mutation was detected by means of a histological method in 23 of 46 cases of PTC and no mutation was found in 22 cases. However, one case was not detected. In using FNABC, BRAF mutation was detected in 6 of 102 cases in cell paucity and in 11 of 74 cases in the atypia. Two cases were not detected in the atypia. The sensitivity and specificity of PCR-RFLP in FNABC were 60% and 97.4% respectively. Assessment of Formalin Fixed Paraffin Embedding (FFPE) block demonstrated similarly a 51.1% positive and 48.9% negative in PTC. Evaluation of BRAF mutation revealed high specificity and low sensitivity in using FNABC method. This study suggests that BRAF mutation analysis should be useful for the clinical diagnosis of PTC in FNABC with cytological findings suspicious for PTC.