• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.3
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• pp.1-11
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• 2007

To evaluate the quality of waste paper used for the manufacture of linerboard, the types of papers and foreign materials in compressed waste paper currently used were investigated. The recycled fibers were obtained from printing paper, newspaper, wrapping paper, white coated paperboard and corrugated container. Their fibers were observed by using a microscope, and the mechanical properties of the recycled papers manufactured from the recycled fibers were investigated. The compressed wastepaper was composed of 54% paperboard, 20% printing paper, and 20% newsprint. The content of foreign materials was about 4%, showing higher contents compared to 1% of foreign substances provided by Korea paper manufacturers' association. The types of foreign materials were various, which include vinyls, plastics, metals, woods, styrofoams, and cloths. Sound fibers were generally observed in the recycled fibers of printing papers and wrapping paper. The recycled fibers of white coated board, corrugated container and newsprint showed to be generally damaged. The whiteness of each recycled fiber were highly affected by pulp bleaching and ink-particle mixing conditions. The values of breaking length and burst index were lower than those for corrugating medium and liner board specified in KS. Although the anatomical characteristics of recycled fibers varied, their strengths appeared to be similar. This result may be explained by the use of non-deinked fiber.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.175-182
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• 2021

Deadlock is a situation in which two or more processes competing for resources are waiting for the others to finish, and neither ever does. There are two different forms of systems, multi-unit and single-unit resource systems. The difference is the number of instances (or units) of each type of resource. Deadlock problem can be modeled as a constrained combinatorial problem that seeks to find a possible scheduling for the processes through which the system can avoid entering a deadlock state. To solve deadlock problem, several algorithms and techniques have been introduced, but the use of metaheuristics is one of the powerful methods to solve it. Genetic algorithms have been effective in solving many optimization issues, including deadlock Problem. In this paper, an improved parallel framework of the genetic algorithm is introduced and adapted effectively and efficiently to deadlock problem. The proposed modified method is implemented in java and tested on a specific dataset. The experiment shows that proposed approach can produce optimal solutions in terms of burst time and the number of feasible solutions in each advanced generation. Further, the proposed approach enables all types of crossovers to work with high performance.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.7-14
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• 2021

Hybrid laminated Al/carbon-fiber-reinforced plastic (CFRP) composites are attracting considerable attention from industries such as aerospace and automobiles owing to their excellent specific strength and specific rigidity. However, when this material is used to fabricate high-pressure fuel storage containers subjected to repeated fatigue loads, fatigue life evaluation for the working load is regulated as an important criterion for operational safety and ease of maintenance. Among the existing evaluation methods for these vessels, the burst test and the hydraulic repeat test require expensive facilities. Thus, the present study aims to develop an improved fatigue life test for Al/CFRP laminated hybrid composites. The test specimen was manufactured using a curved mold considering the shape of a type III high-pressure storage container. The strain-life method was used for fatigue life evaluation, and the life was predicted based on the transition life. The results indicate that the more complex the CFRP stacking sequence, the longer is the transition life. This test method is expected to be useful for ensuring the fatigue safety and economy of hybrid laminate composites.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.623-629
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• 2013

This paper presents the implementation result of the EEG(electroencephalogram) signal transmission protocol and its test platform. EEG measured by a dry-type electrode is directly converted into digital signal by ADC(analog-to-digital converter). Thereafter it is transferred DSP(digital signal processor) platform by $I^2C$(inter-integrated circuit) protocol. DSP conducts the pre-processing of EEG and extracts feature vectors of EEG. In this work, we implement the $I^2C$ protocol with 16 channels by using 10 or 12-bit ADC. In the implementation results, the overhead ratio for the 4 bytes data burst transmission measures 2.16 and the total data rates are 345.6 kbps and 414.72 kbps with 10-bit and 12-bit 1 ksps ADC, respectively. Therefore, in order to support a high speed mode of $I^2C$ for 400 kbps, it is required to use 16:1 and $(8:1){\times}2$ ratios for slave:master in 10-bit ADC and 12-bit ADC, respectively.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.27-37
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• 1993

The purpose of this study was to determine the fluroide release levels of new fluoride-containing liner/base cements and the fluoride uptake by dentin surfaces. Ten specimens of each brand (Fuji ionomer Type III, Fuji Lining LC, Timeline, Vitrebond and XR ionomer) were made, polymerized and placed in fluoride-free distilled water at $37^{\circ}C$, 100% relative humidity for 24 hours. The extracting solution of specimen was exchanged and fluoride release was measured daily for the 30 days. For fluoride uptake study, twenty-five extracted human lower molars were sectioned longitudinally in the mesiodistal direction with a diamond disc. Five teeth were filled with each material and then stored at $37^{\circ}C$, 100% humidity for 4 weeks. Fluoride uptake by dentin from the test materials was evaluated using electron probe micro X-ray analyzer. The following results were obtained : 1. The amounts of fluoride release showed no significant difference between Fuji ionomer Type III and Fuji Lining LC, but showed significant difference between other groups. XR ionomer released significantly greater fluoride than any other group(P<.001). 2. All the materials have a burst effect which more fluoride released in then first 3 day and showed significant decrease over the test period (P<0.001). 3. XR ionomer group showed fluoride penetration to approximately $50{\mu}m$ deep in dentin. But other material groups showed very little fluoride uptake by dentin.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.1-7
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• 2012

Systematic safety research by Korea Government has been made to enhance the safety of CNG (compressed natural gas) vehicles since the burst of compressed cylinder of an urban bus in August 9, 2010. This article summarizes some major activities to ensure the safety of CNG vehicles, which covers review of regulation, safety management system including standard of inspection and certification, and training program of inspectors and car mechanics. Specifically, the followings were reviewed; type of CNG cylinder, location of CNG cylinder, material and type of fuel line and vent line, modification of pipeline connection, installation of gas detector, installation of emergency shutdown valve, installation of protecting cover for cylinder, obligations for CNG vehicle filling station. improving periodical inspection, routine test on gas vehicles, training program for engaged in gas vehicles, and designation of safety manager for CNG bus company. This paper suggests how to improve safety of CNG vehicles as a result of review of above mentioned check items.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.626-634
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• 2012

There are variations among grapevine genotypes in the levels of tolerance to cold, and cold-hardiness of grapevine has been affected by the change of short-term environment during over-wintering. In this study, the responses of vines to cold in open field and rain-shelter system were investigated to obtain useful information in increasing the tolerance to cold in grape cultivation. Total carbohydrate content of bearing mother branches was higher in the rain-shelter system than in the open field, and lower in the branches of 'Muscat Bailey A' than in 'Campbell Early' and 'Kyoho'. Bud-burst and shoot growth were better in the rain-shelter system than in open field, whereas there is no significant difference among the treatments of net beside vines. There was also low incidence of gray mold in rain shelter system. Stilbene compounds such as t-piceid, resveratrol, piceatannol, c-piceid were accumulated in the cold-treated shoot from vine cuts harvested in rain shelter system. Genes of chalcone isomerase, manganese superoxide dismutase, proline rich protein 2, and temperature induced lipocalin were highly expressed in the cold-treated shoot from vine cuts harvested in rain shelter system. While there was not change of air temperature, but high reduction of wind speed in the rain shelter system compared to open field, and increase in the reduction of wind speed by net treatment. The damage of grapevines by cold in the extreme low temperature could be reduced by keeping them in the rain shelter system with net during winter season.

• Progress in Medical Physics
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• v.18 no.2
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• pp.73-80
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• 2007

Fruitful findings have been produced from five out of sixty cells which were obtained from each 63 individual Aplisia caught at the Jeju coast. Spiking patterns of three out of five cells, such as relaxation oscillator, bursting within a short time of the inter-burst interval, chaotic bursting, period doubling sequences, bursting with long trains of action potentials separated by short silent periods, regular repeated beating or elliptic bursting, and silent states had been changed in order as the temperature was lowered to $10^{\circ}C\;from\;32^{\circ}C$. In the intervals of every about 40 minutes repeated ups and downs of temperature produced similar firing patterns at the allowable temperature ranges. The other two cells showed difference from these. The amplitudes of the action potentials of the two cells will not be highly decreased in 24 hours. Average spike frequencies, the inter-burst interval, peak to peak spike amplitude of action potentials, minimum potential values are compared and analyzed by using the computer programme. The spike frequencies according to temperature show the distribution of bell type, with maximal spike frequencies at intermediate temperatures and minimal ones at either end. The most common pattern consist of high spike frequency during failing and low one during rising temperatures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.298-305
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• 2005

Antimicrobial packaging paper was prepared with a powder-type botanical antimicrobial agent from grapefruit seed extract (BAAG) and zeolite according to TAPPI standard method. The functional fillers containing BAAG fixed to CaCO$_3$ and zeolite were well retained in the fiber network by a retention aid such as cationic polyacrylamide, which was ascertained by the ash contents of paper and the SEM microphotographs. With addition of the functional fillers to paper, tensile strength and burst strength of the paper decreased by interference of the functional fillers with interfiber bonding but bending stiffness and tear strength increased by improved elastic modulus of paper and delayed transfer of tearing energy. Finally, it was confirmed that the antimicrobial packaging paper might be able to be used to make packaging bags and corrugated containers due to the minor deterioration of strength properties.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.377-382
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• 2007

Porous mineral coating have been fabricated and applied for basic research on their slow release action to a fertilizer. Feldspar was selected as raw mineral for the coating and two different particle sizes of powder were prepared. Slow-release action was estimated by using a potassium sulfate fertilizer. Spherical pellets were prepared with a pan-type pelletizer and then screened into sizes ranging 1.4 to 2.35mm. While the fertilizer pellets were rotated in the pelletizer again, the feldspar powder and 0.5% polyvinyl alcohol solution were simultaneously sprayed on the pellets. The fertilizer pellets coated with feldspar powder were fabricated. The pellets were heated to increase their strength and screened to sort by coating thickness. Potassium releasing tests were conducted for 40 days and the performance for slow-release action was estimated as functions of the heating temperature, coating thickness and raw mineral powder size. The Burst effect caused high initial releasing rate. Releasing kinetics was proportional to concentration of potassium in pellets. The pellet that was fabricated with $27.4{\mu}m$-sized feldspar and heated at $1050^{\circ}C$ showed a releasing rate of 43% on the 40th day.