• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.327-334
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• 2017

This study was carried out to investigate the formaldehyde emission of building materials and effect of carbonized-board (c-board) on formaldehyde reduction using a chamber method. As a result, reduction performance of formaldehyde was in the order of c-board (90%), c-bamboo board (84%), diatomite-based panel (82%), allophane-based tile (78%), Pinus densiflora timber (58%), MDF (54%) and gypsum-based board (46%) for approximately 12 days. In $1.9m^3$ chamber filled with particleboard (PB), the formaldehyde reduction performance of c-board was significantly increased with increasing input amount of c-board for 68 days. In particular, the formaldehyde emissions can be reduced above 40% and 75% by input rate of 10% and 30% c-board, respectively, in given ratio of chamber volume and PB area.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.3
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• pp.20-26
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• 2013

We investigated practical methods of using recycled gypsum board paper in the paper industry. Gypsum board paper is used to produce construction gypsum board, and can be recycled through the recycling process of construction wastes. The experiments were carried out in two ways: One was the substitution of recycled gypsum board papers for KOCC, and the other was the use of recycled gypsum board paper powder. Recycled gypsum board paper was not disintegrated easily, but high temperature and the use of chemicals were able to improve their disintegration. The physical properties of handsheets made of the pulp of recycled gypsum board paper exhibited the same performance level as those made from KOCC except in the parameter of compressive strength. The powder of recycled gypsum board paper was manufactured using a grinder and handsheets were made with the powder and KOCC. The bulk was increased, but the strength properties were decreased by the addition of the powder.

• Journal of the Korea Furniture Society
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• v.21 no.3
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• pp.237-247
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• 2010

This research was carried out to examine the properties of black charcoal board, in order to find the proper manufacturing condition for the black charcoal-board made of the charcoal. The charcoal in this study was distillated from domestic wood waste, and it were also the purpose of this study to see if the black charcoal-board has the advantageous properties of charcoal as a well-being building material against the sick house problem. Domestic wood waste was consisted of MDF 40%, PB 30%, plywood 15% and wood 15%, respectively. Black charcoal board was produced by hot pressing with following conditions; temperature $170^{\circ}C$, three stage pressing cycle of $40-10-40\;kgf/cm^2$(1min.-2.5min.-5min.) and non formaldehyde adhesives [P15%+M5%:MDI(M), poly vinyl acetate emulsion(P). Fine mixed particle size [#6-12(16.9%), #12-18(16.7%), #12-40(47.2%), #40-60(9.5%), #60-100(5.9%), less than #100(3.8%)] gave better results than larger particle size [over #6(33.8%), #12-18(17.7%), #12-40(37.7%), #40-60(6.4%), #60-100(2.6%), less than #100(1.8%)]. Final moisture content of the mat was best at 36%. Black charcoal-board showed less MOR and IB(internal bond), more WA(water absorption) than that of white charcoal-board. Black charcoal board showed not only the same gas adsorption and dimensional stability as white charcoal board but also good cutting, nailing and drilling for indoor environment systems.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.5
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• pp.418-426
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• 2019

To derive a simplified analytic solution which can be utilized as a fundamental solution for the wave maker design, a segment of the wave board has been idealized as a submerged line segment in a two dimensional domain of a wave flume. The lower end of the line segment could be located at arbitrary depth of the wave flume and the upper end of the board could be also submerged to any depth from the free surface. The freely oscillating motion of the wave board is assumed to be defined by determining the condition of horizontal oscillation on both ends differently. The submerged wave board oscillating in horizontal direction could be specified by selecting the amplitude, frequency and the phase lag differently on lower and upper ends of the board. The simplified two dimensional wave generated by the wave board segment has been obtained by the first order perturbation method. It is found that the general solution of the freely oscillating wave board in two dimensional domain could be decomposed into the solution of flap motion with lower end hinge and swing motion with upper end hinge. The case study of the analytic solutions has been carried out to evaluate the effect on the wave height due to the difference of oscillation frequency, phase difference and variation of stroke between for the motion of both ends. It is found that the solution of the freely oscillating wave board could be utilized for the development of high performance wavemaker especially for irregular waves.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.14-15
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• 2019

The demand for drywall is increasing as the structural type of apartment building is changing to a rigid frame structure. At present, the thickness of the gypsum board used for drywall is mostly 9.5mm and is required to be changed to 12.5mm to improve the performance of the wall. A structural safety test has been conducted in accordance with KS F 2613 to verify the effect of changing the thickness of the gypsum board to 12.5mm in terms of improvement as to stiffness. As a result of the test, the stiffness of the drywall has increased by about 19.6% and the impact resistance by about 30.4%.

• Journal of the Korean housing association
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• v.23 no.5
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• pp.95-102
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• 2012

We studied in order to find out suitable amounts of board by visual effects to establish indoor boards and human psychological effects by several board designs. Thirty students of C university were tested in constant temperature/humidity room and interviewed after tests. The experimental visual images were projected from 54' TV. As a result, the board length that showed high preference and satisfaction was the 90cm both horizontal and vertical direction. We found that vertical board gave an impression of a linear and narrow shape and the horizontal board gave wide space and cool feeling from psychological analytical study. The factors affecting satisfaction in horizontal direction were refreshing, intimacy, beauty, area, splendor and those in vertical direction were a sense of security, beauty, texture, intimacy, continuity, extensity, natural feeling. We got 5 factors from the result of factor analysis in order to get psychological factor axis. Those were pleasantness, artificiality, openness, dynamics, refinement. By multiple regression analysis, the factor pleasantness had the highest impact on visual satisfaction on scenary. The study on psychological factor difference by analysis of variance showed that psychologically feeling amount about pleasantness, artificiality, dynamics, refinement, and openness had statistically meaningful difference despite of board direction. We found that the 90cm had a tendency as a changing point leading image change by the investigative analysis of board direction based on factor points.

• Journal of the Korea Furniture Society
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• v.13 no.1
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• pp.42-47
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• 2002

The folding chairs are one of the most necessary furniture for satisfying the moderns' wants which is utilized for limited space rationally. These folding chairs are variously used in interior spaces such as offices, dining areas, and resting areas. They are very easy to move around, so that quiet useful in out door areas, too. Moreover, they play an important role in public spaces as supplementary furniture. The folding chairs have one or several axes, and they are classified according to type of axes like below. 1. Method of divide seating board into 2 and fold, 2. Method of folds seating board and lay on bottom of backboard, 3. Method of fold back board and lay on top of seating board, 4. Method of fold into contact with left and right, 5. Method of gathering legs into one and fold. The folding chairs have to be easy to operate, firm and safe, light for moving around easily, designed for able to change units whenever they have damaged. Change of residential spaces according to the trend towards the nuclear family maximized necessity of limited spaces' use. Therefore, this study provides insights for development of new methods' of folding chairs.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.15-22
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• 2003

This study was carried out to investigate the properties of sawdust board impregnated with phenol resin according to the density and resin content of board. The sawdust board were manufactured to target densities of 0.4, 0.5, 0.6, 0.7 g/cm³ and resin content of 5, 10, 15, 20% made from Pinus densiflora S. et Z., Larix. kaemferi C. and Pinus koraiensis S. et Z. The impregnation process were executed in two ways, the application of vacuum pressure then followed by atmospheric pressure, and the application of vacuum pressure with ultrasonic vibration then followed by atmospheric pressure. The density of impregnated sawdust board increased as density and resin content of sawdust board increased, but impregnation rate decreased. The density, impregnation rate, bending strength and brinell hardness of sawdust board in impregnated vacuum pressure with ultrasonic vibration then nonpressure were higher than those of vacuum pressure then nonpressure. In this results, the impregnation rate is increased in vacuum pressure with ultrasonic vibration then nonpressure, it has affected the properties of sawdust board impregnated with phenol resin.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.41-48
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• 1986

To investigate the midwater trawl gear available for the Korean near sea trawlers, the authors carried out a field experiment on the attitude and the opening efficiency of the otter board with the Pusan 404 (160GT, 750ps), a training ship of National Fisheries University of Pusan. The experimental trawl gear was designed to be operable by the ship and the otter board was made of single iron plate with 12% camber ratio. The special-prepared potentiometric angle detector was used for determining the attitude, and the 50 KHz fish finder for the opening between the otter boards. The results obtained can be summarized as follows: 1. The angle of attack varied by moving the towing point on the towing plate of the otter board. It showed 33 to 36 degrees when the point was set at the outmost position, 25 to 31 degrees at the middle position and 19 to 30 degrees at the inmost position, with a decreasing tendency according to the increase of towing speed in each cases. 2. The heel of the otter board always occured inwards, increasing slightly according to the increase of towing speed. 3. The tilt of the otter board always occured outwards, increasing slightly according to the move of the towing point inwards, and decreasing slightly according to the increase of towing speed. 4. The opening between otter boards showed the largest value when the towing point was set at the outmost position.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.44-48
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• 1997

The Swedish Fire Research Board was established in 1979 to initiate and fund relevant fire research efforts. The Board is responsible for a long term research programme revised every third year, and the Board is one of two major Swedish sponsors of all fire research. Beside the Board we also have the Swedish National Rescue Services, funded by the government. BRANDFORSK gives very high priority for the industry and the insurance company and the need they express for fire research. Research that the Rescue Services Board are funding is mainly focusing the need for the fire department. The Swedish Fire Research Board, BRANDFORSK, is the joint agency of the Swedish government, the insurance industry and the business sector, for the initiation, funding and supervision of different kinds of fire research. Work is directed by a Programme Board and is performed in the form of projects at universities, research institutes, state authorities and private firms. The Secretariat of BRANDFORSK shares the premises of the Swedish Fire Protection Association, SFPA, and the SFPA is the principal and the party which enters into agreement with the State. The programme for the period 1997-1999 has been drawn up on the basis of both damage development and the trends in society which can be noted, and the evident fire problems of the interested parties and their need for fire research. The inputs in the programme have been broken down seven problem areas. In every problem area different project areas are set out, and these primarily specify the aim of the work. Our seven problem-areas are; Costs and benefits of fire protection measure. The role and behaviour of people and organizations Fire In buildings Fire in underground facilities Rescue operations fire in industries Fire and the environment. In comparison with previous fire research programmes, cost/benefit studies have been accorded higher priority, and this is also reflected in other problem areas. Grater Emphasis