• Computers and Concrete
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• 제23권4호
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• pp.267-272
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• 2019

In order to study the effect of moisture on the compressive strength of low-strength hollow concrete blocks, an experimental study was carried out on 96 samples of locally manufactured hollow concrete blocks collected from three different locations. Uniaxial compression tests were conducted on dry specimens and three types of saturated specimens with moisture contents of 30%, 50% and 80% respectively. The range of moisture content adopted covered the range within which the concrete block samples are saturated in the dry and monsoon seasons. The compressive strength of low-strength hollow concrete blocks decreases with increase in moisture content and the relationship between compressive strength of hollow concrete blocks and their moisture content can be considered to be linear. However, the strength degradation of 30% moist concrete blocks with respect to dry blocks is relatively low and can be considered to be comparable to dry concrete blocks. A formula indicating the relationship between the moisture content and compressive strength of low-strength hollow concrete blocks is also proposed.

• 한국지능시스템학회논문지
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• 제8권6호
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• pp.122-128
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• 1998

이 논문에서는 영상시퀀스의 프레임간 차영상 블록을 영상활동도의 크기 및 분포에 따라 적응적으로 분류함으로써 영상시퀀스를 압축하는 기법을 제안한다. 활동도의 크기에 의한 분류에서는 차영상 블록에 포함되어 있는 물체의 에지부분에 해당하는 활동블록과 비활동 블록으로 분류하고, 활동도의 분포에 의한 분류에서도 활동블록들을 이산 코사인변환계수의 분포정도를 특징으로 하여 수직, 수평, 저활동 블록으로 분류한다. 대표적인 분류결과를 이용하여 RBFN 신경망을 학습시켜 프레임간 차영상 블록들의 비선형적인 분류 특성을 얻었다. 시뮬레이션 결과 RBFN을 이용한 차영상 블록의 분류가 영상활동도의 정렬방법이나 다층퍼셉트론 신경망(MLP)에 비해 영상시퀀스의 압축성능이 향상되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.421-426
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• 2004

Analyzing adaptive possibilities of agents in multi-agents system, we have discovered new aspects of ambient intelligence in distributed modular systems using intelligent building blocks (I-BLOCKS) [1]. This paper describes early scientific researches related to technical design, applicable experiments and evaluation of adaptive processing and information interaction among I-BLOCKS allowing users to easily develop ambient intelligence applications. The processing technology presented in this paper is embedded inside each DUPLO1 brick by microprocessor as well as selected sensors and actuators in addition. Behaviors of an I-BLOCKS modular structure are defined by the internal processing functionality of each I-Blocks in such structure and communication capacities between I-BLOCKS. Users of the I-BLOCKS system can do 'programming by building' and thereby create specific functionalities of a modular structure of intelligent artefacts without the need to learn and use traditional programming language. From investigating different effects of modem artificial intelligence, I-BLOCKS we have developed might possibly contain potential possibilities for developing applications in ambient intelligence (AmI) environments. To illustrate these possibilities, the paper presents a range of different experimental scenarios in which I-BLOCKS have been used to set-up reconfigurable modular systems. The paper also reports briefly about earlier experiments of I-BLOCKS in different research fields, allowing users to construct AmI applications by a just defined concept of modular artefacts [3].

• 패션비즈니스
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• 제11권4호
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• pp.120-134
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• 2007

The usage of basic bodice blocks at men's apparel companies is investigated and the domestic and international men's upper bodice blocks are compared to find directions of research on development of bodice basic blocks. The following conclusions are found in this study. 1. The survey shows that basic bodice blocks are not used at men's apparel companies although all the respondents have good knowledge on bodice basic blocks. They responded that basic bodice blocks for representative body figures of each age category or of each country would help comparative studies on domestic and international basic bodice blocks and development of exporting apparel products. Also, they expected the utilization of men's basic bodice blocks both as education materials and in studies of design, of body figures, and of basic blocks for industry. 2. The comparative study on men's bodice blocks shows that waist circumference, hip circumference, neck circumference, height, and shoulder length, in addition to the minimal essential size items such as chest circumference and center back length, are used in most basic bodice blocks. The size formulae of each basic block are compared to find how the sizes are determined. For center back length, either measured back length or a certain proportion of height is used. For front and back interscyes, chest circumference is used in most basic bodice blocks. Either measured size, or a certain proportion of height or chest circumference is used for back height. The averaged ease allowances of basic bodice blocks are 3.2 cm for chest circumference, 10.8 cm for waist circumference, 1.2 cm for front interscye, 0.1 cm for back interscye, 0.2cm for shoulder length, and 0 cm for center back length. However, body blocks for different types of clothes have different ease allowances. Shirt basic blocks have ease allowances of 6.1 cm for chest circumference, 13.7 cm for waist circumference, 1.4 cm for front interscye, 0.6 cm for back interscye, 1.2 cm for shoulder length, and 1.8 cm for center back length. On the other hand, jacket basic blocks have ease allowances of 8.8 cm for chest circumference, 16 cm for waist circumference, 1.1 cm for front interscye, 1.4 cm for back interscye, 1.1 cm for shoulder length, and 0.8 cm for center back length.

• 조명전기설비학회논문지
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• 제21권10호
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• pp.82-88
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• 2007

이 논문에는 교류전압에서 ZnO 피뢰기 소자의 열적 전기적 특성을 기술하였다. ZnO 피뢰기 소자의 누설전류는 시간의 변화에 따라 측정하였다. ZnO 피뢰기 소자의 온도분포를 열화상카메라에 의해 관측하였다. ZnO 피뢰기 소자의 열화 및 열폭주 현상은 열발생과 열방산을 결정짓는 ZnO 피뢰기 소자의 온도한계와 밀접한 관계가 있다. ZnO 피뢰기 소자의 저항은 ZnO 피뢰기 소자의 온도와 누설전류에 의해 민감하게 변화한다. 결론적으로 ZnO 피뢰기 소자의 열화 및 열폭주 현상은 ZnO 피뢰기 소자의 온도와 소자를 통해 흐르는 누설전류에 상당히 의존적인 것으로 나타났다.

• 대한소아치과학회지
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• 제21권2호
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• pp.577-585
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• 1994

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a $45^{\circ}$ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed: 1. Large overjet and deep overbite were corrected. 2. Class II molar relationship was changed into Class I. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

• 전기학회논문지
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• 제56권8호
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• pp.1484-1490
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• 2007

The Cross Reference Point(CRP) is a robust method for finding salient points in watermarking systems because it is based on the geometrical structure of a normalized image in order to avoid pointing error caused by digital attacks. After normalization of an image, the 100 CRPs are calculated. Next, the 100 blocks centered by CRPS are formed. These 100 blocks are arranged using a secrete key. Each boundary of 50 out of 100 blocks is surrounded by 8 blocks which are selected by the ordered number of a preceding block. This number is a seed of random number generator for selecting 8 out of 50 blocks. The search area of a center block is formed by a secrete key. The pixels of a center block are quantized to 10 levels by predefined thresholds. The watermarks are generated by the 50 quantized center blocks. These watermarks are embedded directly in the remaining 50 blocks. In other words, 50 out of 100 blocks are utilized to generate watermarks and the remaining 50 blocks are used to watermark embedding. Because the watermarks are generated in the given images, we can successfully detect watermarks after several digital attacks. The reason is that the blocks for the generation and detection of watermarks are equally affected by digital attacks except for the case of local distortion such as cropping.

• Structural Engineering and Mechanics
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• 제23권3호
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• pp.293-308
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• 2006

This paper presents a complete and consistent formulation to study the seismic response of a free-standing ship supported by an arrangement of n keel blocks which are all located in a dry dock. It is considered that the foundation of the system is subjected to both horizontal and vertical in plane excitation. The motion of the system is classified in eight different modes which are Rest (relative), Sliding of keel blocks, Rocking of keel blocks, Sliding of the ship, Sliding of both keel blocks and the ship, Sliding and rocking of keel blocks, Rocking of keel blocks with sliding of the ship, and finally Sliding and rocking of keel blocks accompanied with sliding of the ship. For each mode of motion the governing equations are derived, and transition conditions between different modes are also defined. This formulation is based on a number of fundamental assumptions which are 2D idealization for motion of the system, considering keel blocks as the rigid ones and the ship as a massive rigid block too, allowing the similar motion for all keel blocks, and supposing frictional nature for transmitted forces between contacted parts. Also, the rocking of the ship is not likely to take place, and the complete ship separation from keel blocks or separation of keel blocks from the base is considered as one of the failure mode in the system. The formulation presented in this paper can be used in its entirety or in part, and they are suitable for investigation of generalized response using suitable analytical, or conducting a time-history sensitivity analysis.

• International Journal of Concrete Structures and Materials
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• 제7권3호
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• pp.193-202
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• 2013

Geopolymer mortar compressed blocks were prepared using fly ash, ground granulated blast furnace slag, silica fume and metakaolin as binders and sand/quarry dust/pond ash as fine aggregate. Alkaline solution was used to activate the source materials for synthesizing the geopolymer mortar. Fresh mortar was used to obtain the compressed blocks. The strength development with reference to different parameters was studied. The different parameters considered were fineness of fly ash, binder components, type of fine aggregate, molarity of alkaline solution, age of specimen, fluid-to-binder ratio, binder-to-aggregate ratio, degree of saturation, etc. The compressed blocks were tested for compression at different ages. It was observed that some of the blocks attained considerable strength within 24 h under ambient conditions. The cardinal aim was to analyze the experimental data generated to formulate a phenomenological model to arrive at the combinations of the ingredients to produce geopolymer blocks to meet the strength development desired at the specified age. The strength data was analyzed within the framework of generalized Abrams' law. It was interesting to note that the law was applicable to the analysis of strength development of partially saturated compressed blocks when the degree of saturation was maintained constant. The validity of phenomenological model was examined with an independent set of experimental data. The blocks can replace the traditional masonry blocks with many advantages.

• 한국방재학회 논문집
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• 제10권6호
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• pp.165-174
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• 2010

블록 TTG를 이용한 교각국부세굴보호공의 적합성과 유효성을 확인하기 위해 수리모형실험을 통해 모형 블록의 조도계수를 확인하고 안전성을 검토하였다. 현장조건을 대표하는 수리학적 조건하에서 개별 블록과 블록을 연결하여 매트화한 경우의 한계 안전중량을 결정하였다. 사석, 돌망태, TTG의 세굴보수공 성능을 비교한 결과 TTG의 안전성이 가장 우수하였다. 하상재료의 유출을 막기 위해 블록의 중간 부분을 적정한 자갈로 채우고, 토목섬유의 설치 여부를 검토하여야 한다.