• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.180-188
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• 1982

This study was carried out to make hardboard fire retardants and to examine the properties of the hard-board treated with them. The fire retardant treatment was achieved by surface impregnation of water soluble retardant chemicals into the forming mat with 55 percent of moisture content. followed by the hot pressing process. Ammonium monophosphate, ammonium diphosphate, sodium borate, and boric acid were used as the fire retardants. Fire retardant test was carried out by using the differential thermal analysis thermogram. The results are summarized as follows: 1. Fire retardant-treated hardboard showed higher values of the specific gravity. water absoption, and flexural strength than those of untreated hardboard. Especially, the treatment of ammonium monophosphate gave the best results in the flexural strength, and a 10 gr/$ft^2$ loading of the fire retardant compound of ammonium monophoshate, ammonium diphosphate, and sodium borate drew the best flexural strength value among the three different experimental loadings of 10, 20 and 30 gr/$ft^2$. 2. There were no definite differences in moisture content between the fire retardant-treated hardboard and the untreated hardboard. 3. The fire retardant compound of ammonium monophosphate, ammonium diphosphate, and sodium borate resulted in the best fire retardancy, and its fire retardancy was increased in proportion to the increase of loading.

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.283-292
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• 1985

A sanitary quality of a university foodservice establishment was assessed in terms of time and temperature, pH and Aw, and microbiological evaluation. Critical control points during various phases in product flow of fried fish cake soup were identified using hazard analysis concept. The results are summarized as follows : 1) Time and temperature data indicated that phases of holding ingredients at room temperature after cooking, and hot - holding of soup before assembly were critical. 2) pH and Aw values were in favorable for microbial growth. 3) Microbiological data indicated that microbial quality of ingredients was in poor condition. A holding practice of cooked ingredients at room temperature might provide the chance for microbial contamination and multiplication. Hot - holding time and temperature of soup should be strictly controlled to assure the food safety, since the microbial quality of serving food can be directly influenced by the hot - holding temperature of soup. 4) Microbiological test results for food containers, equipments, working surfaces, and supplies indicated that sanitary conditions of earthenware, gloves, wiping cloths and cutting board should be improved promptly. 5) Critical control points identified were : ingredients, pre - preparation, post - preparation, and holding before assembly and service. 6) Guidelines for the effective quality control program for this operation were suggested.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.196-202
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• 2011

Objectives: The aim of this study was to investigate levels of matrix metalloproteinase-8 (MMP-8) and substance P (SP) in root canal exudates during root canal treatment (RCT) of nonvital, painful teeth. Materials and Methods: Patients scheduled for nonsurgical RCT were prospectively selected; the study was performed after obtaining informed consent from the patients and was approved by the Institutional Review Board for Clinical Research of Gangnam Severance Hospital, Yonsei University (3-2008-0118). Canal exudates samples were collected using sterilized paper points from teeth scheduled for RCT across three different time periods. MMP-8 and SP levels were measured using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using a mixed model analysis and the Pearson correlation analysis (p < 0.05). Results: MMP-8 and SP levels in GCF were decreased during RCT (p < 0.0001), and they showed a weak positive correlation to each other (p < 0.05). Patients' subjective pain levels and the response from percussion test were significantly related to SP level. Conclusions: This study demonstrated that periradicular inflammation endodontic origin can elevate SP and MMP-8 levels in root canal exudates. Interestingly, SP level of canal exudates showed a possibility of being used as an indicator of pain due to periapical pathosis.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.409-417
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• 2013

Mu-communication board supported by multi-communication is designed with Atxmega 128A1 which is a low power energy consuming of 8-bit microcontroller. ATxmega128A1 microcontroller consists of 8 UART(Universal asynchronous receiver/transmitter) ports which can be setting appropriate user interface having command line interpreter(CLI) program with each port, 2 kbytes EEPROM, 128 kbytes flash memory, 8 kbytes SRAM. 8 URAT ports are used for the multi communication modem, GPS module, etc. and EEPROM is used for saving a configuration for program running, and flash memory of 128 kbytes is used for storing a Firm Ware, and 8 kbytes SRAM is used for stack, storing memory of global variables while program running. If we uses the hybrid communication of path optimization of VHF, TRS and CDMA to remote control AtoN(aid to navigation), it is able to remove the communication shadow area. Even though there is a shadow area for individual communication method, we can select an optimum communication method. The compatibility of data has been enhanced as using of same data frame per communication devices. For the test, 8640 of data has been collected from the each buoy during 30 days in every 5 minutes and the receiving rate of the data has shown more than 99.4 %.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.644-655
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• 2020

This study focuses on the margin of human error when a navigator is embarrassed by the psychological fear of collision in a close-quarter situation (CQS) and is unable to perform as per the prescribed collision avoidance measures. The purpose of the study is to identify the effects of the navigator's personal characteristics or factors in relation to on-board career (OC), license rating (LR), and age on the perceived collision risk (PCR) in CQSs. In order to obtain quantified data regarding the collision risk perceived by the navigator in four typical CQSs between their own ship and a target ship, this study measured and collated the heart rate variability of 30 navigators on their own ship when two ships approached each other at a speed of 10 knots from 2.5 nautical miles to a collision situation. According to a multiple regression analysis of the measured values, the navigators' OC and LR factors had negative effects on the PCR, while the age factor had no significant effect on PCR. The t-test results showed that the PCR value was significantly higher for navigators with an OC ≤ 4 years than for those with an OC ≥ 5 years, and the LR factor was significantly higher for a class 4~6 group than for a class 2~3. This finding may be applied to the development of collision risk warning systems, particularly for navigators.

• Korean Journal of Adult Nursing
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• v.12 no.1
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• pp.17-29
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• 2000

The purpose of this study is to find out the effects of depression on older adults' metamemory and memory performances. The subjects of the study consisted of 103 older adults over the age of 60 who are living in Kangwon Province. Some data were collected by means of the interview method, using questionnaires for metamemory (MIA questionnaire by Hultsch, et al., 1988), and depression(GDS by Yesavage and Sheikl, 1986). Other data were collected by a testing method on the memory performance, such as the immediate word recall task, the delayed word recall task, the word recognition task(Elderly Verbal Learning Test by Kyung Mi Choi, 1998), and the face recognition task(Face Recognition Task tool developed by this study). The results of this study were as follows: 1) The average point of depressed older persons' metamemory is 3.2 on a 5 point scale and was significantly lower than nondepressed older persons' point of 3.6. Looking into each sub-concept of metamemory, depressed persons' points are higher in terms of task(4.1), but are lower in terms of change(2.3), locus(2.6), and strategy(2.9) in comparison with nondepressed persons' points. 2) Depressed older persons' memory performances are all significantly lower than nondepressed person's, especially in terms of face recognition task(t=7.26, p<.0082) and word recognition task(t=6.58, p<.01). 3) In both depressed and nondepressed persons, metamemory has a close correlation with all memory tasks. In particular, depressed older persons' correlation is higher across the board, especially in memory self-efficacy of metamemory(r=.36 - .49) in comparison with nondepressed persons. 4) According to the results of analysis on the relations between metamemory and memory performances of each memory task using canonical analysis, in the case of depressed older persons, strategy, locus, capability and task have high correlation with word recognition task and delayed word recall task. Also in the case of nondepressed persons, achievement, strategy, change and locus variable have high correlation with face recognition task and immediate word recall task. As mentioned above, depression variables have a negative effect on older persons' metamemory and memory performance. In conclusion, when we care for depressed older persons with less memory ability, we have to consider the outcomes of this study are relevant. In addition, it is necessary to develop nursing intervention in order to prevent memory loss and improve memory performance in depressed older persons.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.99-104
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• 2001

This study surveyed common sense of testing eye vision, feeling of own vision and wearing glasses, and method of wearing glasses using questionnaire for 625 primary student(male 322, female 303) live in Iksan city, Jeon buk Province. The question about the selection of testing vision office answered ophthalmic optics only 12.6% by common sense but 38.8% among testing vision students had been checked the visual acuity in ophthalmic optics. 40% student of all answerer have a poor vision by self-evaluation testing and realized when they look far vision is 46.4% among the poor vision answerer, look black board is 26.0%, look monitor is 18.4%, and reading is 9.9%. 46% answerer of the subjective poor vision who tested eye vision by self-evaluation did not correct eye vision. 48.7% answerer among uncorrect eye vision is because of having no chance to test. The question of effect in wearing glasses answered that the 48% of a1l answerer will be worse the visual acuity, the other is getting better and unchanged eye vision by common sense. The question about how looks like glasses wearer answered that the 45.8% answerer is uncomfortable appearance by common sense. 32.3% answerer of the glasses wearer became a failure wearer because glasses was uncomfortable to fit primary student.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.334-341
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• 2020

The optimum solutions of the instability of the target velocity were studied to solve the case of the target velocity of the ship approaching at a speed of ◯◯knots and deviated by more than ± 10knots, while the surveillance radar rotating speed was varied, while the maximum search range of the radar was evaluated during the operational test & evaluation. The instability of the target velocity did not enable the radar to calculate the information of the target precisely and to degrade the probability of hit and the quality of the target management. The improvement to handle the deviation of the target velocity was optimally determined by using a fishbone diagram to find 9 reasons based on 4M1E, and the algorithm of the target management was identified as the crucial reason. In this study, the improvement was applied to the filter algorithm to stabilize the target velocity in the target tracking management SW by reviewing the current algorithm to find the velocity of the target and recognizing that the problem does not apply to different 𝜶, 𝞫 values when the antenna changed the rotating speed. The ability of the improvement to work was tested on board.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.107-113
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• 1990

This study was attempted to develop a remote controllable speed sprayer in order to protect an operator from agricultural chemicals. For the purpose of remote controllable transmission was developed by using one chip microcomputer. The following results could be summarized in this study. 1. Remote controllable transmission developed had not made even a single mistake during the test performed 100 times repeat. Thus, it could that this machine was very accurate. 2. One chip microcomputer was made by machine language and its was with in 3 sec's which was the same as human did. 3. One chip microcomputer which was used in the experiment could be widely used to automation of agricultural machinery, since it is smaller and chiper than any other similar ones such as personal computer, lap tap, one board computer. 4. Since, farm tractor has the same type of transmission as this system, it also could be adapted to farm tractors. 5. In this experiment, transmission lever was remote controll were designed to operate simultaneously. Thus, this system developed was more complicate than conventional system. However, by removing this transmission lever and by mounting the remote controll system at the speed sprayer, it would be higher and easier to handle than the conventional one.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.407-415
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• 2009

In this research, to identify the degree of preference and participation in leisure sports, over 19-year-old adults living in the capital region were collected as subjects, and among them, 250 persons were chosen by purposive sampling method. Using SPSSWIN 16.0, I analyzed the collected data by reliability analysis, paired sample t-test, PPA(preference performance analysis) method. The conclusion is the following. First, the first quadrant showed wind surfing, skins-cuba, water-ski, and yacht, and as a result of this, it is necessary to improve the degree of participation in this field, the second quadrant showed golf, racketball snow board, ski, fishing, and climbing, and these field need to specific attention to maintain continuous attention, for they have a great deal of attendance, the third quadrant, showed water sleigh, cart, balloon, sky-diving, orienteering, hang gliding, model plane, and survival game. As the degree of preference and participation in these sports is low, it is recommended that more effort should be made for these sports. Finally, in the forth quadrant, there are tracking, mountain bike, inline skates, rafting, and cycling. As it's the participation is high, while that of preference is low, it is important to maintain the policy of the participation in leisure sports. Sencondly, the degree of preference and participation in leisure sport activicties acording to socio demographic characteristics differentiate.