• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.172-178
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• 2017

Thermal property is one of the important characteristic in the field of energetic materials. As the energy material is released during decomposition, DSC(Differential Scanning Calorimetry) is frequently used for the thermal analysis. In case of the dynamic DSC measurements, thermal dynamic change like melting is prevented from the thermal property measurements. And due to the predicting kg scale, the conditions of the heat exchange with the environment significantly is changed. In this study, As the method to resolve the problem, we predict the thermal aging property using the AKTS thermokinetic program from DSC measurements which performed isothermal method. Predicting the thermal aging properties from ARC(Accelerating Rate Calorimetry) measurement, we compare two results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.143-148
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• 2013

When the fault occurs in power system, the fault-current exceeds breaking capacity of the circuit breaker. So, reliablity of the power system is decreased sharply. Superconducting fault-current limiter (SFCL) is operated without impedance in normal state. The fault-current is limited by its impedance during the fault condition. However, the SFCL has several weak points such as huge size, high-price, liquid-nitrogen operation for the real power system. In this paper, We suggested the high-speed interrupter to limit the fault-current in case of the single line-to-ground fault. In addition, we compared the high-speed interrupter with the SFCL to ensure the operation reliability. The proposed interrupter detected the fault-current through the CT, and the power was supplied by operation of the SCR control system. In this experiment, the power of high-speed interrupter was applied after the 4.8[msec] from fault instant. The on-off operation of the interrupter was started after half-cycle from the fault. The fault-current was flowed into the impedance element by the switching operation of the high-speed interrupter. So, the fault current was limited within one cycle, and then it didnt exceed the capacity of a circuit breaker. We confirmed that there was slight difference between the SFCL with high-speed interrupter in terms of limiting-time of the fault-current and switching speed of the SCR. The high-speed interrupter was considered to be more efficient than the SFCL in size, cost or reliability.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.673-680
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• 2001

When the developers develop the software, the cost and time of the software development can be reduced by using blocks that are implemented previously. We call these implemented blocks components. In the early stage of Web-based Instruction, it didn't gain preference in spite of it's benefit of convenience. The main reason is, I think, the lack of generality at the education system which eventually results in unsatisfactory facilities compared with the requirement of teachers and students. And the early systems don't make good use of the plenty data in distributed environment, and don't show so good reliablity due to lack of systematic design and development. In this paper, we suggest WBI developing technology using the concept of WBSE. WBI developing is consist of component of pre-developed education software, integration of component using its reusability, and production of more requirement-satisfactory education software.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.45-50
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• 2004

Currently, structural design of wood structure has been based on ASD (Allowable Structural Design) in Korea. However, the results from this method was known as greater than real value because variations of materials and various conditions were not considered sufficiently. So the study about the design method with probabilistic approach is being performed to overcome this problem. And the standard design method of RBD (Reliability Based Design) has been established and applied. In this study, to apply this method on the domestic wood, the distribution property of the lumber and Glulam was analyzed from the previous report and the basis of the standardized design method was established as soft conversion method from allowable stress used in ASD into reference resistance used in RBD. And through the additional study about the sample size as a important factor to effect on soft conversion, condition to be required in more accurate conversion was evaluated.

• Journal of Cadastre & Land InformatiX
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• v.52 no.2
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• pp.137-152
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• 2022

The cadastral boundary points which cadastral surveyor presented on the ground by conducting cadastral surveying represents the limits of land ownership and give binding force and determination power. However the land disputes have increased these days mainly due to cadastral registration errors, surveying errors and land owners recognition error. In these cases, the cadastral survey interests try to find solution by either a administrative procedures by appealing civil complaint or border determination litigation through court. The neighboring residents and related organization have difficulties in resolving the civil complaints. In this study cadastral surveying and cadastral boundary determination process has been reviewed and the results of cadastral surveying screening by Central Cadastre Committee from 2016 to 2021 have been classified. The outcomes of this research will be used for cadastral surveying and contribute for reducing land disputes and improve reliablity of cadastral surveying.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.683-690
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• 1998

The purpose of this study was to evaluate the reliablity of laser Doppler flowmeter on the permanent maxillary central incisors with open apex. Laser Doppler flowmeter and electric pulp tests were done in 35 elementary students aged between 8 and 9 years and 35 females and males aged between 23 and 24 years. Teeth with open apex were confined to root developmental stage 5 and 6 by Moorrees classification. The threshold of electric pulp tests was decided the time of tingling sensation. More than three different electric pulp tests applied on every teeth with more than 3 minutes interval between each teeth due to the false response. Laser Doppler flowmeter test stablilzation and observation stages took more than 5 minutes each LDF values and electric pulp test thresholds were analyzed with student t-test. The results were as follows: 1. The electric pulp test threshold on teeth with immature and mature roots showed 28.4% and 100% response respectively, and the the LDF values on teeth with immature and mature roots showed 100% response. 2. The EPT thresholds on teeth with immature roots were larger than thresholds on teeth with mature roots(p<0.01). 3. No significant differences were found in the LDF values on teeth with immature and mature roots.

• Korea Journal of Hospital Management
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• v.3 no.1
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• pp.192-218
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• 1998

This study is the positive one about the influence which the characteristics of medical consumers' perceived words-transmission information exercises on its acceptance level and its activities. The aim of this study was to investigate how the characteristics-reliability of perceived information, its directionity, and its availability-had an influence on the acceptance level and activities of words-transmission information. For the purpose of that aim, the positive research by questionnaire was applied. In addition, to collect necessary data, investigation was performed about 20 days from July 1st, 1938 to July 20th, 1938. As for the respondents' sampling in sample planning, the method of Simple Random Sampling was used laying stress on patients or their responsible person aged over 20s in second and third medical institutions. And the collected sample were 230 people. Of these, However, the number of sample used actually for this study analysis was 211 except 19 people who responded unfaithfully. The analysis of the data collected by the abovesaid investigation used SPSS/PC statistical package. The study result to have proved the hypothesis by experiment is as follows. First, as the result of having analysed the influence relations on the acceptance level and activities of words-transmission information among the factors of reliability about medical consumers' perceived information, I found that 'specialty' had an affirmative effect and there was a significant effect relations. Second, as the result of having made a multi-regression analysis of the effect relations on the acceptance level and activities of words-transmission information of the factors of directionity on medical consumers' perceived information, 'reliablity' was found as having a significant effect on the acceptance of words-transmission information. Third, 'importantness' was revealed as having a significant effect on the words-transmission activities in the acceptance level and activities of words-transmission information among the factors of reliability on medical consumers' perceived information. Fourth. for medical consumers there was a statistical correlation between the acceptance level and activities of words-transmission information. Therefore, words-transmission communication will be very useful for hospital promotion programs having a limited advertising ability in business. Especially, I suggest that a person in charge of his/her hospital marketing should not only excavate a source of words-transmission communication in order to arrive effectively at sampling market, but also use a marketing mix suitable to that The test result shows that the unsatisfied patients over their hospital treatment tend to be more stronger in transmitting words to the other positive minded patients than the satisfied ones. Therefore, all relating representatives in hospital should concentrate their energies on decreasing or eliminating these unwanted results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.109-116
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• 1988

The strength and load of structure are varied with the Passage of time, and become a process of probability. It is possible to estimate the reliability from the relation between strength and load. Considering the safety, It is reasonable to estimate allowable stress from the safety factor based on the reliability. In this study, the method to estimate probability of fracture, which is index of reliability for rail subjeict to long term fatigue load were examined. In estimation of reliablity it is meaningless to evaluate numerical value especially this difficult case estimating parameter of random variable. To overcome this problem, conventional design method estimating relative reliability were proposed. In this study the Cornell method were examined. The uncertainity of random variale, ie coefficient of variation which is the index of variation of strength and load were considered. The effect of uncertainity related to probability of fracture, and safety factor based on reliability were examined. The results of this study are followed. The reliability of weld metal were influenced by variation of strength more then load, and base metal were influenced by load. It is confirmed that the allowable stress range calculating with factor of safety based an reliability is conservative.

• Development and Reproduction
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• v.5 no.1
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• pp.59-71
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• 2001

Since the first radioimmunoassay (RIA) was developed in 1970s, many conventional RIAs and non-isotopic immunoassays (NIA) had been developed in which the degree of precision, accuracy, specificity and practicability have progressively increased. Recently ultrasensitive assay method at femtogram to determine testosterone in serum, saliva and feces is required for the study of sexual dysfunctions in male and female, monitoring the psychological stress and conditions, aging process such as menopause and partial androgen deficiency in aging male, the hormonal changes of small experimental animals etc. This review discussed the recentd evelopments of steroid assay methods, based upon the testosterone assay results of authors far 20 years, and the problems associated the assay set-up, the characterizations and applications of the established procedures, and desifls of assay, reliablity criteria, and the practical aspects of assay set-up and application, based upon the data of the authors. The present study demonstrates the general problems methods to be consider in order to set up the highly sensitive assay methods and to increase the assay quality and the necessity of assay quality control program. To improve the assay quality of each laboratory and to compare the assay results in homeland, the national QC programs should be organized.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.361-369
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• 2016

Oral health can influence on diverse food intake, and food intake affect oral health related quality of life. The aim of this study was to select key foods to be able to represent oral health related quality of life in Korea. We used the data of 503 Korean older persons to participate in the oral health promotion programme in 2009. The low consumption or low intake foods with criteria in 2012 National Nutrition Statistics were eliminated among 30 foods of food intake ability (FIA) at first. Decision tree model, correlation analysis, factor analysis, and internal reliablity test were used for oral health related quailty of life (OHRQoL) key food selection. We selected 13 foods-hard persimmon, dried peanut, pickled radish, caramel, rib of pork, glutinous rice cake, cabbage kimchi, apple, yellow melon, boiled chicken meat, boiled fish, mandarin, noodles as OHRQoL Key Foods 13. Thirty foods of FIA and OHRQoL Key Foods 13 displayed the same pattern of variation among sociodemographic groups. In a regression model, both of 30 foods of FIA and OHRQoL Key Foods 13 influenced on oral health impact profile-14. The findings suggest that OHRQoL Key Foods 13 have good reliability and validity and be able to use in oral health survey.