• Macromolecular Research
• /
• v.15 no.7
• /
• pp.656-661
• /
• 2007

The effects of a neutral solvent of dioctyl phthalate (DOP) on the phase behavior of symmetric polystyrene-block-poly(n-butyl methacrylate) copolymers (PS-b-PnBMA) were assessed herein. Closed-loop phase behavior with a lower disorder-to-order transition (LDOT) and an upper order-to-disorder transition (UODT) was observed for PS-b-PnBMA/DOP solution when the quantity of DOP was carefully controlled. When the molecular weight of PS-b-PnBMA became larger, the LDOT did not appreciably change at smaller quantities of DOP. With larger quantities of DOP, the reduction in the UODT is greater than the increase in the LDOT. This behavior is discussed in accordance with a molecular theory predicated on a compressible random-phase approximation.

• Journal of the Korean Chemical Society
• /
• v.24 no.3
• /
• pp.259-265
• /
• 1980

Poly (styrene-b-methyl methacrylate) (PS-b-PMMA) was synthesized by free radical telomerization: the telomerization of styrene with $CCI_4$ by using AIBN as initiator followed by a second telomerization of methyl methacrylate using $CCI_3$ end group of the resulting polymer as the macrotelogen, with AIBN initiation, gave the styrene-methyl methacrylate block copolymer. The effects of the concentration of the macrotelogen, the concentration of monomer, the molecular weight of the macrotelogen, the reaction temperature and the concentration of the solvent on the formation of the block copolymer were investigated. Block copolymers containing up to 10 weight percent PMMA were obtained by adjusting the reaction conditions.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.5
• /
• pp.317-322
• /
• 2014

Data security and integrity is a critical issue in data transmission over wired/wireless links. A large amount of data is encrypted before transmission, by block cipher using mode of operation. RBF mode is a block cipher mode of operation which uses random characteristics. In this paper, we analyze the safety against known plaintext attack and chosen plaintext attack of RBF mode compared to the traditional modes. According to the analysis, RBF mode is known to be secure while the traditional modes are not secure against them.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.3 no.2
• /
• pp.74-78
• /
• 2010

Since the extent of use of musculoskeletal ultrasound in orthopaedic surgery is expanding, popliteal block(sciatic nerve block) and femoral nerve block(saphenous nerve block) are easily and safely performed without complications such as nerve injury or incomplete block. Also, due to the expanding use of ultrasound, orthopaedic surgery of not only foot but also ankle and lower leg could be done without general anesthesia or spinal anesthesia. We describe a detailed technique for ultrasound-guided femorosciatic nerve block based on the experience over 120 cases.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.10
• /
• pp.2645-2652
• /
• 1996

In this paper wepropose a sub-block retransmission scheme for ARQ and hybrid ARQ schemes. When the cannel is quiet the sub-block retransmission scheme behaves like a conventional ARQ or hybrid ARQ scheme. As the channel is becoming noisy, the data block is dvided into small sub-blocks for transmission. Each sub-block is encoded for error control by an apprpriate shortened code and the code length of the shortened code is being adaptive to the corresponding channel BER. the reeived block is checked for errors sub-block by sub-block. The propsoed sub-block retransmission scheme provides improved throughput over conventional schemes by retransmitting only the naked sub-blocks in the occurrence of errors. An example of transferring ATM cells is considered for simulation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.6
• /
• pp.568-572
• /
• 2006

This paper presents the device of recognizing image of the studded paving blocks, transmitting, the information by vibration to a visually handicapped person. Usually the blind uses the walking stick to recognize the studded paving block. This research uses a PCA (Principal Component Analysis) based image processing approach for recognizing the paving blocks. We classify the studded paving blocks into 5 classes, that is, vertical line block, right-declined line block, left-declined line block, dotted block and flat block. The 8 images for each of 5 classes are captured for each block by 112*120 pixels, then the eigenvectors are obtained in magnitude order of eigenvectors by using principal component analysis. The principal components for images can be calculated using projection of transformation matrix composed of eigenvectors. The classification has been executed using Euclidean's distance, so the block having minimum distance with a image is chosen as matched one. The result of classification is transmitted to the blind by electric vibration signals with different magnitudes and frequencies.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2005.11a
• /
• pp.229-234
• /
• 2005

The purpose of this study is to analyze a Characteristics of block formation and commercialization of residential books commercial area along urban arteries on Teheran-ro in Seoul. 'Teheran-ro' is selected as a case site to analyze the characteristics of residential blocks commercial area along urban arteries. The study analyzes the characteristics of the street network and block formation in commercial area along arteries and rear residential blocks, and commercialization of residential blocks commercial area along urban arteries according to the characteristics of street network and block formation. The analysis about block formation progress about i ) a street network and block formation, ii ) the scale of blocks, iii) division of lots, iv) lots system. The analysis about commercialization of residential blocks commercial area progress about i) a street network and block formation, ii) a density of building, iii) a use of building

• Journal of the Korean Home Economics Association
• /
• v.41 no.7
• /
• pp.185-200
• /
• 2003

The purpose of this study was to investigate the fitness using the draft method to develop moderate-stretch knit block pattern for young women in Korea. The subjects were three women within the range of the ages from 18 to 24 showing the average body figures. In this study, 4 different patterns were drafted for the moderate stretch knitted fabrics, that were categorised into two different types. The first type of these was made up for kilted fabrics and the other was initially drafted for woven fabrics and altered for knitted materials afterward. The major findings derived from this investigation were as follows; 1. According to each sensory evaluation for the appearance test on fitness, knit block patterns A and D were the better than the rest of them. 2. Knit block patterns A and D with higher evaluation scores were drafted with body size measurements except the waist line, whereas patterns B and C with relatively lower scores were produced including the smaller ease amounts than the woven block pattern. 3. To see the results of the functional test based on the designed ten motions for this experiment, knit block patterns A and B were concluded as better than the rest of them. In addition, concerning the arm liking motions, pattern B was scored as the best among the developed patterns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.2
• /
• pp.40-45
• /
• 2007

This study analyzed the resistivity characteristic of model block to make the good use of structure grounding and substitution grounding electrode base of building. After making the model block of mortar and concrete block, it measured resistivity in hydrous condition and dry condition and compared with the blocks that is mixed earth resistance lowering agent to decrease resistivity. The resistance value of block accepted much influence by block resistivity. When the block resistivity was same or similar value, the value of soil resistivity has occurred as different as the value of grounding resistance.

• Journal of Sensor Science and Technology
• /
• v.24 no.2
• /
• pp.124-130
• /
• 2015

This paper presents a high performance HIGHT processor that can be applicable for CCM mode. In fact, HIGHT algorithm is a 64-bit block cipher. However, the proposed HIGHT extends the basic block length to 128-bit. The proposed HIGHT is operated as 128-bit block cipher and it can treat 128-bit block at once. Thus, it can be applicable for the various WSN applications that need fast and ultralight 128-bit block cipher, in particular, to be operated in CCM mode. In addition, the proposed HIGHT processor shares the common logics such as 128-bit key scheduler and control logics during encryption and decryption to reduce the area overhead caused by the extension of data block length. From the simulation results, the circuit area and power consumption of the proposed HIGHT are increases as 40% and 64% compared to the conventional 64-bit counterpart. However, the throughput of the proposed HIGHT can be up to two times as fast. Consequently, the proposed HIGHT is useful for USN and handheld devices based on battery as well as RFID tag the size of circuit is less than 5,000 gates.