• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.3-26
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• 1985

The object of this study was to investigate the effects on physical and mechanical properties of wood particle and sawdust board combined with wire net. Conventional forming, press-lam, and veneer comply boards combining one to four wire net sheets were made from wood particle and sawdust with different spacings (8, 10, 12, and 18 Mok) and different wire diameters (0.35, 0.50, and 0.80mm) composing wire net. They were compared and analyzed statistically with specific gravity, thickness swelling, length swelling, bending properties (modulus of rupture, modulus of elasticity, work to proportional limit, and total work), internal bonding strength, and screw holding strength between wood particle and sawdust boards. The results obtained at this study as cording to the discussions might be concluded as follows; 1. In specific gravity, both particle and sawdust boards by press-lam method were higher than by conventional forming and veneer comply method, and the boards containing more wire net sheets also showed higher value. But the wire net spacings(Mok) had no influence on specific gravity. In general, particle board showed higher specific gravity than sawdust board. Veneer comply board showed lowest specific gravity values. 2. Both particle and sawdust boards by press-lam method was slightly lower than by conventional forming and veneer comply method in thickness swelling. The sawdust board containing 8, 12. and 18 Mok wire net showed lower thickness swelling than the corresponding particle board, but both sawdust and particle boards containing the T8 and 10 Mok wire net showed higher and similar thickness swelling. 3. Both particle and sawdust boards containing wire net showed no difference in MOR and MOE of bending. Comply board was the highest and particle board showed slightly higher than sawdust board in MOR and MOE values. 4. In work to proportional limit and total work in bending, both particle and sawdust boards containing thicker wire diameter and more wire net sheets showed higher value. From these facts, it is conceivable that boards with thicker wire diameter and more wire net sheets show increasing resistance against external force. But there was no significant difference between particle and sawdust borads. 5. In resistance against delamination (internal bonding strength), both sawdust and particle boards containing wire net showed lower value than control, and also showed decreasing tendency with more number of wire net sheet composed. Particle board showed higher resistance against delamination than sawdust board. 6. In screw holding strength, sawdust board containing thicker wire diameter and more wire net sheets showed higher value, but particle board by press-lam method was higher than by conventional forming and veneer comply method. Screw holding strength of particle board was higher than that of sawdust board.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.1
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• pp.145-155
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• 2018

The matter of cultivating entrepreneurship and will to start a business of university students majoring in agriculture and life sciences and college students majoring in agriculture as a future leader in the sector is a very important object of study. However, the discussion on entrepreneurship, establishment of a business and venture based on creative technology and innovative management have been scarcely had, because traditionally the majority of agricultural business has been a small-sized and simple business run by a small farmer. Education for starting an agricultural business in agriculture industry has been ignored even in the developed countries. ICT and AI(artificial intelligence)-based smart agriculture in the 4th Industrial Revolution Age is emerging as a new growth potential of our agriculture industry. Thus, the interest in farmers to start a business and venture agriculture is growing in the agriculture industry. Accordingly, the study draws the influence factors regarding the effect of the planned behavior of the university students who take part in the education course for starting an agricultural business and an agricultural venture business on entrepreneurship and will to start the business and conducts the empirical analysis. The businessmen who newly join the agriculture industry should perform the technical innovation and the creative business activities to be able to compete in the agriculture industry.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.89-97
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• 2006

Purpose : To evaluate MR image qualities we developed a new MRI phantom with the fixation structures necessary to position it into coil firmly. Materials and methods : We designed MRI phantom for eight evaluation items such as slice thickness accuracy, high contrast spatial resolution, low contrast object detectability, geometry accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting and signal to noise ratio. For the positioning of phantom at coils, the fixation structures were set up on the surface of phantom. Six different MRI units were used for test the possibility for the clinical application and their image qualities were evaluated. Results : We acquired appropriate MR image qualities enough for the evaluation on all used MR units and confirmed that their evaluations were within reliable values compared to real ones for some items. The positioning of our phantom into head coils with fixation structures worked well for proper imaging. Conclusion : We found that our prototype of MRI phantom had the possibility of clinical application for MR image quality assessment.

• Journal of Korean society of Dental Hygiene
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• v.1 no.1
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• pp.1-17
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• 2001

This study was tried to suppose the necessity for the participations of the guardians or parents into dental health educations and for developing an educational program on the control of denial health in order to improve the dental health of handicapped children. For this research, it was investigated by a survey on the actual condition of dental health with an object of handicapped children, and simultaneously by analyzing the relationships between the realities of child's dental caries and guardian's acknowledgments and managements with regard to the dental health of the children. The 209 children and their guardians being in special school for the handicapped were surveyed about the actual conditions of dental health from 15 May to 30 June 2000. 1. The average of DT, MT, FT and DMFT index were 2.46, 0.13, 1.18 and 3.78, respectively. 2. As the parents' educational level (p<0.05) and economical incomes were high, the proportions the DMFT index were low (p<0.05). As the father of the handicapped children had a duty, the DMFT index were lower than the opposite case that the father had no duty. However. in the case of their mother, the presence of the duty has not showed any relationships with the DMFT index. And it was revealed that there was a tendency that the lower age of the parents showed the lower proportions (p<0.05) and index (p<0.001). 3. There was no meaningful differences for the DMFT index in the comparison between the children who can brush themselves or not, even though the children who can brush themselves showed relatively and slightly lower DMFT index than the children who can't do it themselves. 4. More frequent observations on the children's dental conditions by the parent resulted in the lower DMFT index(p<0.01). 5. As the parent had relatively more knowledges about the dental disease. the DMFT index were low. Therefore, as it was considered form these results, the parent should be required more positive participations for the improvement of their children's dental health. For promoting this participations, it must be required the development of educational programs and political services for the parent or guardians in order to improve the attendance into the educations.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.453-465
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• 2014

The purpose of this study was to find out the change in psychological well-being of middle school students by participating in after school physical training activities. To achieve this object, 100 male students of M middle school in K city. "Teenagers' psychological well-being measurement tool" developed by Chung-hee Park(2007). Twice a week, for twelve weeks, the experimental group took part in an after school physical training activity, and the control group, in non-physical classes. The conclusion reached based on the result of this study are as follows. First, there was a statistically significant difference in the change of the family relations factor. Second, there was no statistically significant difference in the change of the student-teacher relations factor between the group Third, there was a statistically significant difference in the change of the self-awareness factor between the group. Fourth, there was no statistically significant difference in the change of the self assertiveness factor between the group. Fifth, there was a statistically significant difference in the change of the friendship factor between the group. Sixth, there was no statistically significant difference in the change of the self-initiative studying factor between the group. In conclusion, taking part in an after school physical training activity on a regular basis can increase the feeling of care and love from family relations, give positive self awareness and attitude towards life, and help building mutual trust between friends by having close relationship.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.95-100
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• 2007

Busan-port is world's fifth trading port and is playing an important role in medium of revenue expansion and civic growth of Busan metropolitan city. Therefore, Busan metropolitan city aims at establishment of maritime special city with sailing of popular election third times. But this sort of goal can be accomplished when job satisfaction of port's personnel concerned is elevated. So, the object of this study is to research on job satisfaction of Busan-port pier management corporation's employee. Through the examination of preceding studies, duty contents promotion remuneration control sense of responsibility colleague relation guarantee job office quantity working environment. tenure of office sex age education are used as factors of job satisfaction. The finding of this study are as follows; First, promotion and remuneration exert significant influence upon job satisfaction. Second, the job satisfaction of Busan-port Pier Management Corporation's Employee is pretty low.

• Journal of Conservation Science
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• v.36 no.2
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• pp.123-142
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• 2020

We attempted an experimental study of lost-wax casting to reconstruct the Gilt-bronze pensive Bodhisattva; The main object we aimed to reconstruct was the Korean national treasure No.83, Gilt-bronze pensive Bodhisattva(Maitreya); thus, we scientifically analyzed and measured the alloy ratio and casting method. Initially, the alloy ratio we used during the preliminary experiment was Cu:Sn:Pb = 95.5:4.0:0.5; we then increased tin and lead by 2.5% to consider vaporization during the main experiment. After applying lost-wax casting, we realized that 30% rosin contributed to proper hardness after the wax hardness experiment. The microstructure revealed normal casting character(α-Cu, δ), and the results of the chemical analysis are identical to those of previous studies. The analysis of the mold suggests the presence of quartz powder for structural stability and fire-resistance along with other organic materials whose contribution is still unknown. We expect that our research will serve to provide basic data for advanced studies in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.865-871
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• 2011

Presently, the location and direction information are certainly needed for the autonomous vehicle of the ship. Among them, the direction information is a essential elements to automatic steering system. And the gyro-compass, the magnetic-compass and the GPS compass are the sensor indicating the direction. The gyro-compasses are mainly used in the large-sized ship of the GMDSS(Global Maritime Distress & Safety System). The precision and the reliability of the gyro-compasses are excellent but big volume and high price are disadvantage. The magnetic-compass has relatively fine precision and inexpensive price. However, the disadvantage is in the influence by the magnetism object including the steel structure of a ship, and etc. In the case of the GPS compass, the true north is indicated according to the change of the location information but in case of the minimum number of satellites or stopping of a ship or exercise in the error range, the exact direction cannot be obtained. In this paper, the performance of the GPS compass was improved by using the least-square curve fitting method for the mutual trade off of the angle sensor. The algorithm which improves the precision of an azimuth by applying the weighted value according to the size of covariance error was proposed with GPS-compass and magnetic compass. The characteristic and the performance of the proposed algorithm were analyzed and verified through experimentation. The applicability of the proposed algorithm was shown through the experimental result.

• Journal of Korea Water Resources Association
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• v.43 no.10
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• pp.865-881
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• 2010

To evaluate influence of the future climate change on water environment, it is necessary to use a rainfall-runoff model, or a basin model allowing us to simultaneously simulate water quality factors such as sediment and nutrient material. Thus, SWAT is selected as a watershed-based model and Nakdong river basin is chosen as a target basin for this study. To apply climate change scenarios as input data to SWAT, Australian model (CSIRO: Mk3.0, CSMK) and Canadian models (CCCma: CGCM3-T47, CT47) of GCMs are used. Each GCMs which have A2, B1, and A1B scenarios effectively represent the climate characteristics of the Korean peninsula. For detecting climate change in Nakdong river basin, precipitation and temperature, increasing rate of these were analyzed in each scenarios. By simulation results, flow and increasing rate of these were analyzed at particular points which are important in the object basin. Flow and variation of flow in the scenarios for present and future climate changes were compared and analyzed by years, seasons, divided into mid terms. In most of the points temperature and flow rate are increased, because climate change is expected to have a significant effect on rising water temperature and flow rate of river and lake, further on the basis of this study result should set enhancing up water control project of hydraulic structures caused by increasing outer discharge of the Nakdong River Basin due to climate change.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.1
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• pp.1-15
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• 2000

To reconstruct 3- D shape, It is a common strategy to acquire multiple range Images from different viewpoints and integrate them into a common coordinates In this paper, we particularly focus on the registration and integration processes for combining all range Images into one surface model. For the registration, we propose the 2-step registration algorithm, which consists of 2 steps the rough registration step using all data points and the fine registration step using the high-curved data points For the integration, we propose a new algorithm, referred to as ‘multi-registration’ technique, to alleviate the error accumulation problem, which occurs during applying the pair-wise registration to each range image sequentially, in order to transform them into a common reference frame Intensive experiments are performed on the various real range data In experiments, all range images were registered within 1 minutes on Pentium 150MHz PC The results show that the proposed algorithms registrate and integrate multiple range Images within a tolerable error bound in a reasonable computation time, and the total error between all range Images are equalized with our proposed algorithms.