• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.607-615
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• 2016

The delamination along the annual ring on the cross-section of laminae and the bonding strength according to the tangential angle between laminae were evaluated for the production of 3-ply cross-laminated timber (CLT) using domestic larch. Since there is no standard for CLT in Korea, the production and test of specimens for bonding strength followed the standard procedure of "Structural glued laminated timber" (KS F 3021). The standard specifies to exclude any measurement from the cracks of timbers resulted from drying or knots during delamination test of the glued laminated timbers. However, the failure of cross-sectional tissues along the annual rings was observed near the glue-line of all specimens during the delamination test. Because this phenomenon can generate defects in the CLT that may be exposed to various temperatures and relative humidities after the actual construction, the delamination percentage was measured by including this wood failure. As a result, the delamination percentage of the CLT which had been combined in such a way that the annual rings of outer lamina were directed inward was the lowest, which was around 13%, regardless of the annual ring direction of the middle lamina. On the other hand, the delamination percentage of the CLT which had been combined in such a way that the annual rings of outer lamina were directed outward was the highest, which was around 26%. Furthermore, end-split occurred in the outer lamina during the drying process of the boiling delamination test, which affected the delamination percentage. Therefore, the soaking delamination test was found to be more appropriate for evaluating the delamination strength of CLT. The block shear strength of larch CLT was $3.9{\pm}0.9$ MPa on average, which was 46% lower than the block shear strength requirement (7.1 MPa) of the standard, but satisfied the criteria of the block shear strength (3.5 MPa) of the European Standard (prEN 16351: 2013).

• Journal of the Korean Geotechnical Society
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• v.32 no.5
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• pp.37-48
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• 2016

This study aims to figure out the behavior of runoff and drainage of pervious sidewalk block in actual construction environment by experiments. The specimens with surface layer and bedding layer are subjected to the drainage test by considering unsaturated condition and unique rainfall condition in urban areas. The repeated drainage test and clogging test were conducted with time intervals, and 3D X-ray CT image analysis and evaporation test were carried out for a quantitative analysis of drainage test. The results present that the spatial distribution of pores by evaporation for time intervals induces runoff. Especially, the bedding layer under the block is significantly critical in overall hydraulic behavior such as drainage and evaporation compared to the surface layer. Moreover, the sediments in pores promote the change in pores by evaporation and this induces deteriorated drainage capacity which is hard to recover. In addition, it is revealed that the maximum runoff height grows as the drainage capacity declines depending on the pre-wetting condition.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.977-987
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• 2023

The purpose of this study was to investigate the effect of visual information on the dynamic balance on Y-balance Test(YBT). The subjects of the study were 18 male and female adults in their 20s and 30s (age: 23.17±1.72 years, height: 172.46±9.84 cm, weight: 73.39±11.44 kg, leg length: 88.89±5.69 cm) who participated in the study. To measure dynamic balance between binocular and monocular use, absolute reach distance, composite score, and COP variables were measured on left and right feet through YBT and results were derived. As a result of the study, monocular block(left and right eye block) showed higher absolute reach and composite scores than binocular use in posterolateral, posteromedial, and composite scores during YBT. As a result of COP, there was no difference in anterior and posteromedial reach. When reaching posterolateral, AP COP velocity of left foot in monocular block appeared slower than that in binocular vision, and in COP velocity, COP velocity of left foot in monocular block appeared slower than binocular vision.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.5 s.236
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• pp.663-670
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• 2005

DIN CK35 (JIS S35CK) steels have been used as a material in fuel pump blocks for marine engines. Failures in the inner surface of a drilling hole, due to the initiation of fatigue cracks have been frequently reported. However, the mechanism initiating these cracks and growths has not been clearly diagnosed yet. This study was conducted using a scraped fuel pump block, containing an initiated fatigue crack in the inner surface of a drilling hole. Initially, the cracks and fractured surfaces inside the block were investigated using an optical microscope and a SEM (Scanning Electron Microscope). In addition, microstructure observation, fatigue life test and fatigue crack growth test were performed using a specimen, which was taken from the same block. Results from these tests are summarized as follows; (1) The early crack in the block was supposed to occur inside the inner surface of the drilling hole. (2) The fatigue endurance of this material was about 330 Mpa. (3) The early crack was generated in the cavitations created by the breakdown of a big inclusion, or separation between the big inclusion and the base metal, in which the fundamental ingredients of the inclusion were C, 5, and Mn. (4) In order to prevent these types of failures, the suppression of inclusions inflow by improving the casting process, formation of fine inclusions by applying a heat treatment process, and coating of the surface of the drilling hole were required.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.87-97
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• 2008

This research focused on development and application feasibility for the coalesced continuous block system in river bank protection. Most of block systems in river bank are pre cast type and have some difficulties against high velocity flood condition or high pressure load, however, the continuous block system can be applied to flood damage recover as well as environmental vegetation block system in river bank. For the application review and analysis of hydraulic condition for this block system, hydraulic physical modeling was carried out. The physical model was built as a scale of 1:50 by Froude similitude measuring the water levels and the water velocities for vegetation application or not. In consequence, the water velocities were observed to decrease meanly 10.1%, and the water depths were to increase meanly 17.8% in case of the of design flood, $Q=200m^3/sec$. To verify the hydraulic physical modeling, the numerical modeling should be conducted for a close examination of vegetation application by one or two dimensional numerical analysis as a next study.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.2
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• pp.187-199
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• 2009

Recently, the quality and design of the children's wear is being improved remarkably. Following the trend, the need for the research on the pattern making of children's wear is growing. At first, we tried to find out how the industry is doing the pattern making job through interview. Results are as follows. The target age ranges from 5 to 11 years old. For the sample size of pattern making, 7 years of age is preferred. It is not usual to develop the design pattern from the bodice block pattern. Instead, they use middle block pattern for each item, such as blouse, shirt, pants, skirt or jacket. Starting from these middle block pattern, they prepare individual designs. With the results, the aim of the research became to develop one of most frequently used middle block pattern. The blouse block pattern was selected for that purpose. To look into the existing patterns, we selected 4 methods, i.e. NM-method, T-method, O-method, E-methods. Theses patterns were compared through wearing test for the evaluation of comfort and fit using trial garments. The results indicated the NM-method was best among them. Specially waist line position, shoulder shape and size allowance was adequate. Alteration and adjustment of pattern draft was made onto the NM-method. Allowances for the bust circumference, across chest, across back and depth of arm was adjusted for better comfort as well as fine fit. Sidelines of the bodice and the underarm seam of the sleeves were curved for styling. After another wearing test, the final pattern was suggested as a blouse block pattern for 7 years old girl.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.75-80
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• 2017

Permeable block pavement systems are widely used to relieve the flood and enhance water circulation. However, domestic design method has not yet been established well. Although AASHTO 93 flexible pavement design method is applied as a structural design method outside the country, there is a lack of information on layer coefficient of the permeable pavement materials, which makes it difficult to apply the design to various materials. Therefore, in this study, a method of calculating the layer coefficient of permeable block pavement materials by plate load test was presented and the layer coefficient of a permeable block pavement in a testbed was evaluated. Overall, calculated layer coefficient of open graded aggregate and permeable block pavement surface layer were similar to those of the conventional values. The presented method may be used to evaluate layer coefficients of permeable block pavements for design.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.186-191
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• 2019

In this paper, we propose a implementation approach of the high-speed feature extraction algorithm. The proposed method is based on the block type classification algorithm which reduces the computation time when target macro block is divided to smooth block type that has no image features. It is quantitatively identified that occurs at 29.5% of the total image using 200 standard test images with $64{\times}64$ macro block size. This means that within a standard test image containing various image information, 29.5% can reduce the complexity of the operation. When the proposed approach is applied to the Canny edge detection, the required latency of the edge detection can be completely eliminated, such as 2D derivative filter, gradient magnitude/direction computation, non-maximal suppression, adaptive threshold calculation, hysteresis thresholding. Also, it is expected that operation time of the feature detection can be reduced by applying block type classification algorithm to various feature extraction algorithms in this way.

• Journal of KIISE:Software and Applications
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• v.37 no.10
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• pp.768-772
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• 2010

Concolic testing generates test data by combining concrete program execution and symbolic execution to achieve high test coverage. CREST is a representative open-source test tool implementing concolic testing. Currently, however, CREST aims at exploring all possible execution paths. In case of testing a specific branch or block, thus, it can be ineffective. This paper suggests a goal-oriented concolic testing that generates test data to execute a given branch or block.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.62-66
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• 1996

Since 1980, Korea Research Institute of Standards and Science (KRISS) have performed 8 round robin tests in gauge block measurement in order to evaluate the measurement capability and the state of environment control of National Calibration and Test Institutions. Two sets of five gauge blocks (nominal size : 1, 3, 10, 25, 100 mm) having different thermal expansion coefficients for each set were circulated for the measurement, and the measurement results were collected and analyzed to evaluate the traceability to the standard of KRISS. The method and results of the test are presented.