• 한국학교수학회논문집
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• 제3권1호
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• pp.101-115
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• 2000

Development of new and highly efficient computer technologies are providing schools and homes with faster and multi-functioning computers, and text-oriented education softwares are now being rapidly replaced by multimedia CAI. There are also increasing needs for computer-literate teachers and more effective CAI materials. The goal of this study is to present effective ways to use computers as teaching aids in mathematics classrooms and how computers affect the students' achievement, interest and attitude in mathematics. Theoretical reviews on learning theories of CAI and multimedia were made before designing teaching plans for mathematics classrooms and the plans were applied to classrooms. The result of this study shows that there is a significant difference in achievement between control group and experimental group, and also indicates that CAI increases the students' interest and attitude in mathematics to a certain extent. Although using computers in classrooms are considered to be more effective in teaching than text-oriented lectures, the number of computers in schools is limited and all the students can not take advantage of individualized drill and practice programs or tutorial programs. One way of various solutions to this problem is developing teaching materials for middle or large sized classes and providing teachers with easy-to-carry notebook computers. And also mathematics teachers should be given more chances to train themselves in developing and using CAI materials.

• 한국생산제조학회지
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• 제8권1호
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• pp.81-88
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• 1999

This paper was carried out to know the influence of advanced austempered ductile cast iron (ADI) on the tool life and mechanical properties of drilling machinability. For manufactured method of ADI, the spheroidal graphite cast iron were austenized at 90$0^{\circ}C$ for 1 hour and then austempered for 2 hour at 37$0^{\circ}C$ in the salt bath. And interrelationship has been investigated between tool life and mechanical characteristics of specimen material on drilling condition when the ordinary and step-feed drilling are carried out to drill holes of specimens. Tensile strength and hardness of ADI decrease and elongation of ADI increases with the increase austempered temperature. It is known that about 2 times of tool life in the case of step-feed decreases compared with ordinary feed due to the high hardness of ADI and hardness ascribed to the fact that retained austenite became to martensite state due to cutting heat in drilling. Under the constant feed rate 0.1mm/rev relation between hardness and length of end tip after drilling can be formularized to Hv=$788.46L^{-0.096}$ for the cutting speed 6.1m/min.

• 한국학교보건학회지
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• 제23권2호
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• pp.143-150
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• 2010

Purpose: This study aims to examine what can be seen in children's paintings, their common characteristics, and what role art therapy plays in diagnosing the post-traumatic stress disorder in children who experienced trauma, through an art therapy program among elementary school students that witnessed the death of parents from a fire drill accident. Methods: A program of three times of art therapy was progressed among 34 children who witnessed a fire accident. Revised Children's Manifest Anxiety Scale (RCMAS) was used for comparative analysis of art therapy results. Results and Conclusion: First, children who had the possibility to develop post-traumatic stress disorder were found through art therapy. Second, an opportunity to express themselves were given to children who refused psychological tests or treatment through art therapy.

• 한국생활과학회지
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• 제11권4호
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• pp.381-389
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• 2002

This research was designed to investigate the preference to textiles for slacks of college students. 105 subjects majored in fashion design were surveyed. Subjects selected three favorite materials among 120 samples presented in swatch book and weighted frequency and percentage were added by order. The extent of preference was compared by season and sex. The results of this study were as follows: 1. College students preferred twill cotton Drill foremost as a textile for spring and fall season. 2. Plain linen Crash was the most preferred material for summer. 3. Cotton Corduroy was the most preferred textile for winter. 4. In thickness and weight, textiles for winter were thicker and heavier than those of other seasons. 5. In fiber content, natural fiber such as wool were preferred for all seasons. 6. In weave of textiles, twill weave fabric was preferred for spring fall and winter season, and plain weave for summer. 7. College students preferred plain texture materials foremost and navy blue and black color was preferred for textiles for slacks. 8. Girl students preferred cotton fabrics and boys preferred wool fabric for slacks. Also, girls generally preferred thinner fabrics than those of boys.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.227-238
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• 1993

IRRI Engineering Division has developed a well drilling rig attachment that matched power tiller or hand tractor. It was designed in response to the growing demand for ground water utilization for small-scale irrigation, especially in drought-sticken and rained farms in Asian countries. The power tiller-driven rig can drill 30 meters of 100mm well in an unconsolidated formation in one day and can be rapidly converted from rotary to jetting or to the percussion method of drilling to suit different soil and rock formation. In addition, the power tiller can be quickly installed or removed from the rig frame and can be used for transporting the rig to other sites. The rig can be dismantled into smaller sub-assemblies for carrying by hand into less accessible areas. One manufacturer in Central luzon Philippines has started to produce the rig for well drillers in Central Luzon. The Department of Agriculture in the Philippines have procured thirty three(33) units of these machines f r their Shallow Tubewell program.

• 방사성폐기물학회지
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• 제15권4호
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• pp.301-312
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• 2017

The concept of deep borehole disposal (DBD) for high-level nuclear wastes has been around for about 40 years. Now, the Department of Energy (DOE) in the United States (U.S.) is re-examining this concept through recent studies at Sandia National Laboratory and a field test. With DBD, nuclear waste will be emplaced in boreholes at depths of 3 to 5 km in crystalline basement rocks. Thinking is that these settings will provide nearly intact rock and fluid density stratification, which together should act as a robust geologic barrier, requiring only minimal performance from the engineered components. The Nuclear Waste Technical Review Board (NWTRB) has raised concerns that the deep subsurface is more complicated, leading to science, engineering, and safety issues. However, given time and resources, DBD will evolve substantially in the ability to drill deep holes and make measurements there. A leap forward in technology for drilling could lead to other exciting geological applications. Possible innovations might include deep robotic mining, deep energy production, or crustal sequestration of $CO_2$, and new ideas for nuclear waste disposal. Novel technologies could be explored by Korean geologists through simple proof-of-concept experiments and technology demonstrations.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.455-459
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• 2008

This study defines the Next Generation System(NGS) built by domestic financial businesses and classifies their architecture into two typical types according to the duration of the project and the relative cost of IT investment in the short term: the Big Bang approach and the Phase approach. Herein, we study the two approaches as alternatives in developing the Next Generation System, and derive the factors that are to be considered in the evaluation of the two alternatives for financial businesses. The set of standards for the choice between the two models are grouped into categories that constitute performance evaluation for IT - Cost, Performance and Risk. We drill down further into each category to second and third subordinate levels to derive detailed selection criteria. Based on the criteria drawn from the study, we conduct a survey with information system planners, IT managers and specialists at financial companies who are currently planning, developing or have completed a Next Generation System. Survey results are analyzed using the AHP methodology to compare and understand the different approach in the implementation of NGS for financial business.

• Journal of Korean Neurosurgical Society
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• 제57권1호
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• pp.54-57
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• 2015

A 66-year-old woman presented with intermittent paraparesis and generalized tonic-clonic seizure. Cerebral angiography demonstrated dural arteriovenous fistula (AVF) involving superior sagittal sinus (SSS), which was associated with SSS occlusion on the posterior one third. The dural AVF was fed by bilateral middle meningeal arteries (MMAs), superficial temporal arteries (STAs) and occipital arteries with marked retrograde cortical venous reflux. Transfemoral arterial Onyx embolization was performed through right MMA and STA, but it was not successful, which resulted in partial obliteration of dural AVF because of tortuous MMA preventing the microcatheter from reaching the fistula closely enough. Second procedure was performed through left MMA accessed by direct MMA puncture following small decortications of cranium overlying the MMA using diamond drill one week later. Microcatheter could be located far distally to the fistula through 5 F sheath placed into the MMA and complete obliteration of dural AVF was achieved using 3.9 cc of Onyx.

• 한국군사과학기술학회지
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• 제14권1호
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• pp.139-146
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• 2011

This study investigated physical and physiological changes of normal young adults, who are cadets of the Air Force Academy, have kept long-term physical activities and healthy behavior. The physical and physiological indices were the blood and body composition. Data were collected at the first year period, and then 4th year period from same group of cadets. The amounts of blood components were not changed, but variation among cadets was significantly reduced in the 4th grade period. The red blood cells(RBCs) were significantly reduced and the concentration of hemoglobin(HGB) were significantly increased. The body weight was significantly decreased in the 1st grade period since the body fat was rapidly decreased after the basic military drill, and then it was recovered with building up of the skeletal muscle in the 4th grade period. Asymmetry of the arms was decreased with the increased physical activities and usage of various equipments. The muscular endurance were significantly enhanced in the 4th grade period. The long-term physical activities and healthy behaviors may keep the physical strength through enhanced blood stream and oxygen supply by reduction of the RBCs and increased HGB concentration, and fat and muscle control.

• 한국군사과학기술학회지
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• 제14권1호
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• pp.15-21
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• 2011

In this paper, the results of experimental analysis for the chemical composition and strengh verification of Bailey Panel Bridge have been presented. Some of main sections of bailey bridge colllected from military engineer troops were prepared for the chemical composition and strengh verification. The composition test and strength verification were conducted by using the optical microscope and Scanning Electron Microscope(SEM), Automatic Control Spark Emission Spectrometer(OBLF), X-ray Fluorescence Spectroscopy(XRF) and Instron measurement. The results showed that currently used sections of bailey bridge passed the strength verification and could be operated in drill of troops and battle fields.