• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.242-250
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• 2017

Purpose: This study was conducted to determine the appropriate operating conditions through a factorial experiment for the secondary separating part of the self-propelled pepper harvester. Methods: An experimental setup that simulates the secondary separating part of the self-propelled pepper harvester was organized. Test samples were classified into three types according to the number of peppers on a stem, and 12 sets were prepared for each type. Among the operating conditions of the secondary separating part, the rotational speed of drum B (four levels), radial clearance between drums and cylindrical teeth (three levels), and speed ratio between the three drums (two levels) were set as the test factors, and tests were repeated three times for different levels of each factor. The appropriate operating conditions were determined by analyzing the separation ratio and damage ratio of the peppers collected through the secondary separating part. Results: The test factors changed the overall separation ratio and overall damage ratio in similar trends. In other words, the conditions that caused high overall separation ratios also exhibited high overall damage ratios. Owing to the high overall damage ratio in the condition with the highest overall separation ratio, the operating conditions should be selected considering both ratios. Conclusions: When the condition with more than 60% of overall separation ratio and less than 15% of overall damage ratio was considered as the appropriate operating condition, 70 rpm of the rotational speed of drum B, 5 mm of the radial clearance between drums and cylindrical teeth, and 7:3:5 for the speed ratio of the three drums A, B, and C should be applied for the secondary separating part used in this study. Supplementary studies will be required in the future to find optimal operating conditions through the actual field test under further divided test factors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.5-8
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• 2003

This paper presents a methodology to be able to select an appropriate RP system that suits the end use of a part. Evaluation factors used in process selection include major attributes such as accuracy, roughness, strength, elongation, part cost and build time that greatly affect the performance of RP systems. Crisp values such as accuracy and surface roughness are obtained with a new test part developed. The test part is designed with conjoint analysis to reflect users' preference. The part cost and build time that have approximate ranges due to cost and many variable parameters are presented by linguistic values that can be described with triangular fuzzy numbers. Based on the evaluation values obtained, an appropriate RP process for a specific part application is selected by using the modified TOPSIS(Technique of Order Preference by Similarity to Ideal Solution) method. It uses crisp data as well as linguistic variables, and each weight on the alternatives is assigned by using pair-wise comparison matrix. The ranking order helps the decision making of the selection of RP systems.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.418-425
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• 2016

This paper presents the part-of-speech set which is highly efficient at knowledge-based word sense disambiguation for Korean nouns. 174,000 sentences extracted for test set from Sejong semantic tagged corpus whose sense is based on Standard korean dictionary. We disambiguate selected nouns in test set using glosses and examples in Standard Korean dictionary. 15 part-of-speeches which give the best performance for all test set and 17 part-of-speeches which give the best performance for accuracy average of selected nouns are selected. We obtain 12% more performance by those part-of-speech sets than by full 45 part-of-speech set.

• Journal of KIISE:Information Networking
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• v.28 no.2
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• pp.277-287
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• 2001

Test derivation methods suitable for interoperability testing of communication protocols were proposed in [1,2, 3] and applied to the TCP and the ATM protocols, The test cases that were generated by them deal with only the control part of the protocols. However, in real protocol testing, the test cases must manage the data part as well. For complete testing, in principle we must test all possible values of data part although it is impractical to do so. In this paper, we present a method generating the interoperability test suite for both the data part and the control part of protocols with the example of Tep connection establishment. In this process, we make use of experimental design techniques from industrial engineering to minimize the size of test suite while keeping testing capability. Experimental design techniques have been used for protocol confom1ance testing but not for intcruperability testing so far. We generate the test suite for data part by this method and show a possibility that we can test interoperability of protocols with the minimum number of test cases while maintaining the testing power.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.29-39
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• 2010

This paper presents and analyzes laboratory test results of distributed translator (DTxR) for distributed frequency network (DFN) in the ATSC (Advanced Television Systems Committee) terrestrial digital TV broadcasting system. The DTxR laboratory test is classified to receiving part test and transmitting part test. The receiving part test includes dynamic range, random noise, single echo, and adjacent channel interference. The transmitting part test includes quality of output signal (out-of channel emission, quality of transmitting signal, and phase noise), frequency synchronization among output signals, and TxID (Transmitter Identification) signal's affect to the legacy receiver. By the laboratory test results, the receiving part of DTxR eliminates average -2.5 dB of single echo and has average 17.5 dB at TOV (Threshold of Visibility) under random noise environment. In addition, the transmitting part of DTxR satisfies the specification of US FCC (Federal Communications Commission), and frequency difference among DTxR output signals is less than 0.001 Hz.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.123-133
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• 2016

The purpose of this study was to examine the part-time work experience of nursing students and its effects on their interpersonal communication competence, self-efficacy and social skills. The study subjects were 362 nursing students in areas S, B, G and G. The relationship between the nursing students' part time work. experience and their general characteristics was analyzed by the Chi-square (${\chi}^2$) test and Fisher's exact test. The interpersonal communication competence originating from the general characteristics, self-efficacy, and difference in the social skills standard among groups were analyzed by the t-test, and analysis of variance (ANOVA). Among the 326 participants, 91.7% had part-time experience and 8.3% had no part-time experience. There was a significant relation between the part-time experience and economic level. Those having a low economic level were more likely to have part time work experience. The interpersonal communication and social skills of the students who had part time work experience when they were middle school students were lower than those who had such experience after high school. Further research is needed to identify precisely the advantages afforded by the part-time work experience of the nursing students.

• Journal of Integrative Natural Science
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• v.5 no.4
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• pp.241-245
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• 2012

Categorical data collected based on complex sample design is not proper for the standard Pearson multinomial-based chi-squared test because the observations are not independent and identically distributed. This study investigates effects of bias of point estimator of population proportion and its variance estimator to the standard Pearson chi-squared test statistics when the sample is collected based on complex sampling scheme. This study examines the effect under two population homogeneity test. The standard Pearson test statistic can be partitioned into two parts; the first part is the weighted sum of ${\chi}^2_1$ with eigenvalues of design matrix as their weights, and the additional second part which is added due to the biases of the point estimator and its variance estimator. Our empirical analysis shows that even though the bias of point estimator is small, Pearson test statistic is very much inflated due to underestimate the variance of point estimator. In the connection of design-based variance estimator and its design matrix, the bigger the average of eigenvalues of design matrix is, the larger relative size of which the first component part to Pearson test statistic is taking.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.1
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• pp.35-39
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• 2017

The engine is the most significant and essential part of the aircraft. As a result, systematical handling in the aircraft development stage is required from engine design to implementation to the full-scale airframe. This survey demonstrates the procedures demanded by the KAS 23 Civil Aircraft to acquire the engine Type Certification and the flight test procedures for ensuring the operational stability. Surveys were conducted on domestic and international aircraft engine certifications, technical regulations and documentations related to the Means of Compliance for flight test development stage. In addition, organized reference items that should be considered for the certification of engine flight test procedures were reviewed based on the KC-100.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.4
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• pp.33-40
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• 2006

In present study, the principal stress condition needed to conduct cubical large-scale triaxial test which can reflect three dimensional stress condition (or plain strain condition) in a dam was investigated by performing model test and numerical analysis and the principal stress ratio varying with the height of CFRD was examined. Also, the principal stress ratio in CFRD body was investigated from the monitoring results of horizontal and vertical earth pressure gages, installed in the center zone and lower part of transition zone of the dam body, respectively, in order to consider the principal stress condition in the large-scale triaxial test to model the behavior of CFRD. The result of the study indicated that the principal stress ratio decreased gradually from the lower to the upper part in the dam body for its center axis and was about 0.5 and 0.2 in the lower and upper part, respectively.

• Journal of Gifted/Talented Education
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• v.8 no.2
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• pp.69-89
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• 1998

The purpose of this study is to develop a test which can be used in identification of the gifted students in the area of mathematics. This study was carried out for two years from 1996. Mathematical giftedness is, in this study, regarded as a result of interaction of mathematical thinking ability, mathematical creativity, mathematical task committment, background knowledge. This study presumed that mathematical thinking ability is composed of seven thinking abilities: intuitive insights, ability for information organization, ability for visualization, ability for mathematical abstraction, inferential thinking ability(both inductive and deductive thinking abilities), generalization and application ability, and reflective thinking. This study also presupposed that mathematical creativity is composed of 3 characteristics: fluency, flexibility, originality. The test for mathematical creative problem solving ability was developed for primary, middle, and high school students. The test is composed of two parts: the first part is concentrated more on divergent thinking, while the second part is more on convergent thinking. The major targets of the test were the students whose achievement level in mathematics belong to top 15~20% in each school. The goodness of the test was examined in the aspects of reliability, validity, difficulty, and discrimination power. Cronbach $\alpha$ was in the range of .60~.75, suggesting that the test is fairly reliable. The validity of the test was examined through the correlation among the test results for mathematical creative problem solving ability, I. Q., and academic achievement scores in mathematics and through the correlation between the scores in the first part and the scores in the second part of the test for mathematical creative problem solving ability. The test was found to be very difficult for the subjects. However, the discrimination power of the test was at the acceptable level.