• 한국초등과학교육학회지:초등과학교육
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• 제28권2호
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• pp.154-160
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• 2009

Correlational reasoning is used to analyze results from an experiment and create meaningful relationships among variables. Although there were many recognition development studies, not a single study found the optimal period for the development of logical thinking. Therefore, the purpose of this study is to find the optimal period for students whose logic for variable controlling and correlational reasoning are poor. This study made a logic program treatment subject for students between the 4th and 8th grade whose recognition in reasoning has not been developed in general in order to find the optimal period for their development. The variable-controlling reasoning was performed the program of voice survey and sugared-water melting in subsection survey and sugared-water melting in subsection. And, the correlation reasoning was performed the program of rat's size and tail color, treatment, and effect. As a result of research, students, who were not formed variable controlling and correlational reasoning, could be known to be enhanced through learning, but to fail to be formed the qualitative change like the cognitive development. In other words, the optimal period couldn't be found that is grown the formation of students, who are not formed the variable controlling and correlational reasoning, through learning. It is expected that this research can contribute to the improvement of students' cognitive level and there would be more active researches in different fields to improve the cognitive level.

• 패션비즈니스
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• 제6권3호
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• pp.41-51
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• 2002

The author of the paper investigated the changes of hairstyle along the developments in hairdressing industry in the 20th century. The development process of hairdressing industry was divided into four periods of introduction, origination, growth, and establishment. The corresponding changes of hairstyle were analyzed and the findings are as follows. 1. Hairstyle could be classified into such typical ones as traditional style, cut, bob, wave, permanent wave, up style, and hair coloring. 2. Fashion leaders affected the changes of hairstyle. 3. Whenever hairdressing appliances were introduced, new hairstyle was practiced as follows with the use of the appliances. (1) Introduction Period - Traditional Style : Chignon, pigtail ribbon $\rightarrow$ Variations were designed in hair length or split due to the limited availability of appliances. - Up Style : Pompadour, thick and up hair, encircling hair $\rightarrow$ Padding was used for sweep-up. (2) Origination Period - Bob Style : Women's first bob style. - Wave style : Wave with bob, close-cropped hair, up style $\rightarrow$ Iron, set, permanent devices were used. (3) Development Period - Wave Style : Wind wave, easily manageable wave $\rightarrow$ Blow dry, body permanent were used. (4) Establishment Period - Straight Style : Use of straight permanent. - Thick Wave Style : Development of various kinds of rod. - Hair Coloring : Advent of diverse fashion hair coloring, apart from the coloring of white hair, with the introduction of color TV. - Bob Style : Romantic bob style $^{\circ}\hat{E}$ Use of clippers and thinning scissors. Thus, the changes of hairstyle according to the development in hairdressing industry had close relationship with the improvement in hairdressing appliances.

• 한국토양비료학회지
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• 제50권6호
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• pp.674-683
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• 2017

The frequency and intensity of soil moisture stress associated with climate change has increasing, and the stability of field crop cultivation has decreasing. This experiment was conducted to investigate the effect of soil moisture management method on growth and yield of corn. Soil moisture was managed at the grade of WSM (wet soil moisture, 34.0~42.9%), OSM (optimum soil moisture, 27.8~34.0%), DSM (dry soil moisture, 20.3~27.8%), and ESM (extreme dry moisture, 16.6~20.3%) during V8 (8th leaf stage)-VT (tasseling stage). After VT, irrigation was limited. The treated amount of irrigation was 54.1, 47.7, 44.0 and 34.5% of total water requirement, respectively. The potential evapotranspiration during the growing period was $3.29mm\;day^{-1}$, and upward movement of soil water was estimated by the AFKAE 0.5 model in the order of ESM, DSM, OSM, and WSM. We could confirm this phenomenon from actual observations. There was no significant difference in leaf characteristics, dry matter, and primary productivity depending on the level of soil moisture, but leaf development was delayed and dry weight decreased in DSM. However, dry weight and individual productivity of DSM increased after irrigation withdrawal compared to that of OSM. In DSM, ear yield and number of kernels per ear decreased, but water use efficiency and harvest index were higher than other treatments. Therefore, it is considered that the soil moisture is concentratedly managed before the V8 period, the V8-VT period is controlled within the range of 100 to 500 kPa (20.3~27.8%), and no additional irrigation is required after the VT.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.102-107
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• 2004

New designed floating breakwater made of Polyethelener with considering the introduction of new material for being harmony with environment and stability of the floater is developed for a marine ranching. Model experiment in order to test its capability is performed for the regular and irregular waves in ocean engineering basin. Good capability to break the incident wave within the 6 second of period and 1 m of height is shown. Breaking efficiency for long period wave is not so good in regular and irregular wave. The results of this study will contribute to the design and construction of the floating breakwater.

• Fisheries and Aquatic Sciences
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• 제11권1호
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• pp.41-49
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• 2008

Internal waves and internal tides occur frequently along the eastern coast of Korea. During the spring-tide period in April 2003, the East Korean Warm Current (EKWC) flowed near the Korean East Coast Farming Forecast System (KECFFS; a moored oceanographic measurement system), creating a strong thermocline at the intermediate layer. Weakened stratification and well-mixed water appeared frequently around the KECFFS, with duration of approximately 1 day. The results suggest the following scenario. Baroclinic motion related to the internal tide generated high frequency internal waves around the thermocline. The breaking of those waves then created turbulence around the thermocline. After well-mixed water appeared, a current component with perpendicular direction to the EKWC appeared within the inertial period. The change in stratification around the KECFFS locally broke the geostrophic balance as a transient state. This local vertical mixing formed an ageostrophic current within the inertial period.

• Journal of Nutrition and Health
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• 제19권5호
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• pp.333-341
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• 1986

Several aspects including physical development, reflex acquistion, neuromotor development and learning behavior at Y water maze were compared at the progeny of rats fed low 91.2mg/kg diet) or adequate leves(22mg/kg diet 0 of pyridoxine during growth, gestation, lactation, and adult period. Physical development and development of reflexes (righting reflex, cliff avoidance, negative geotaxis, palmar grasp, and startle reflex to sound) appeared different between control and deficient groups but not significantly. At the 2nd week, rats spent more time in supported standing during 6 minute period was longer in the control then the deficient groups. In the Y-water maze position reversal test, learning ability as judged by the number of errors was not different among three groups, but the rats in supplemented group(DC) reached the escape platform in significantly shorter time than the other two groups, which may suggest their emotional instability. In the visual discrimination test, the performance of rats from the supplemented group had the lower errors than the other groups on the early test days. but as the testing period progressed, the performance of rats in the supplemented group became inferior to those of the control and deficient groups. The performance of control group became superior to that of the deficient group.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.995-1000
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• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• 아동학회지
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• 제37권3호
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• pp.83-93
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• 2016

Objective: This study examined that general characteristics such as gender, age, period of stay at an institution, size of facility, and temperament and attachment affect young children's development under institutional care. Methods: A total of 94 young children (ages 2-4years), who live in 32 institutions in Seoul were assessed on their development using the Korean-Age & Stage Questionnaire. Pearson productmoment correlation analysis, and multiple regression analyses were used for data analysis. Results: The major findings of this study were as follows: first, a longer period of stay at an institution had more positive effects on the development of communication. Facilities with more than 60 children had lower communication, gross motor, and fine motor development compared to facilities with less than 60 children. Second, social temperament had positive effects on communication, problem solving, and personal-social development. Emotional temperament had no effects on all development areas. Third, attachment had positive effects on all development areas. Lastly, social temperament and attachment had interactive effects on communication, gross motor, problem solving, and personal-social development. Conclusion: These results imply that caretakers in institutions should give developmental mediation services for considering temperament and facilitation of attachment.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.703-705
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• 1996

CALS (Commerce At the Light Speed) is considered one of the most important concepts in the 21th century. In the period of CALS, the roles of telecommunication companies to prepare for CALS period. They are: development of facilities management, participation of virtual enterprise prototype, providing teleconference tool, execution of BPR, development fo customer management system.

• 제어로봇시스템학회논문지
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• 제7권10호
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• pp.843-848
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• 2001

Most of gimballed inertial navigation systems(GNIS) are calibrated periodically to maintain their inherent accuracy. The existing calibration techniques using the conventional schuler test with the least square method and the multiposition test take a long time and have some problems in procedures. To solve this problem, calibration method using a linear Kalman filter is proposed by us. In this paper, the calibration method by the change of Schuler period is studied in order to improve the calibration performance of the gimballed INS. First of all, it is shown that the observability of Kalman filter is also enhanced the Schuler period is decreased. Simulation results show that the calibration performance using the present scheme is improved according to the decrease of the Schuler period and the calibration time is shortened extremely, too. And our proposed technique shows desirable estimation performance for the g-sensitive errors of inertial sensors in particular.