• 한국보육지원학회지
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• 제20권1호
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• pp.39-53
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• 2024

Objective: The purpose of this study is to investigate whether emotionality at age three predicts early school-age media overdependence and to examine the potential mediating role of internalizing behavior problems in children. Methods: This study employed data from the 4th and 10th waves of the Panel Study of Korea Children, comprising a sample of 1,270 children. Assessments of emotionality (4th wave), media overdependence (10th wave), and internalizing behavior problems (10th wave) were conducted. Data analysis utilized SPSS and the Process Macro. Results: At age 3, heightened emotionality was found to directly contribute to an increased tendency for media overdependence in early school age. Internalizing behavior problems played a significant mediating role in the relationship between emotionality and media overdependence. Conclusion/Implications: This study validated a significant longitudinal connection between emotionality and the inclination to excessively rely on media, highlighting the role of internalization behavior problems in this relationship. It is essential to provide focused attention, especially to children displaying heightened emotionality in early childhood, in order to proactively prevent internalization behavior problems and the undue dependence on media.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2720-2724
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• 2007

Field measurements have revealed that the pressure drop over a borehole during drilling of a slim oil well or a well with a long reach can depend significantly on the rotation speed of the drill pipe. An accurate prediction of the annular frictional pressure drop is therefore important for conditions where the annular clearance is small. An experimental study was carried out to study solid-liquid two phase flow in a slim hole annulus. Annular velocities of carrier fluids varied from 0.2 m/s to 1.5 m/s. The carrier fluids which were utilized included tap water and CMC water solutions. Pressure drops and average flow rates were measured for the parameters such as inner-pipe rotary speed, carrier fluid velocity, hole inclination and particle injection rate. For both water and CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become.

• Journal of Biosystems Engineering
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• 제30권1호
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• pp.1-7
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• 2005

When a slope tractor works on the slope land, it travels usually along the contour and slope line. In that case, the efficiency of work generally decreases and the safety of the operator caused by the overturn of the tractor should be considered. Maintaining the tractor body being horizontal during the travel is crucial to solve problems. To overcome such a problem, an automatic leveling control system for slope tractor has been developed. The system composed of sensor for measuring rolling and pitching inclination of the slope tractor chassis, controller, hydraulic control system and mechanism. The limit angle of the leveling control was set up to be ${\pm}15^{\circ}C$ for rolling, ${\pm}7^{\circ}C$ for pitching. The proposed control and hydraulic power system was implemented to the prototype slope tractor. This paper shows results about development of the automatic leveling mechanism and response properties for slope tractor.

• 농업과학연구
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• 제38권2호
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• pp.343-347
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• 2011

Precise traveling and tillage operation using an autonomous tractor is difficult with the data from the Geographic Information System(GIS) because it does not include the data of the width and inclination of the field to work. The minimum turing radius of the tractor could be different from the value presented by the tractor maker due to the moisture content of the field soil or operators' skill. Two programs were developed to process data obtained with the tillage path measuring system: one for recognizing coordinates of the 4 field corners, and the other for recognizing the minimum turning radius of the tractor.

• 설비공학논문집
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• 제9권2호
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• pp.153-162
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• 1997

In this study, the wet surface heat transfer coefficients and friction factors of the heat exchanger with slit-wavy fin were measured. Four sample cores of two or three row with fins of 12 fpi or 16 fpi were tested. Tests were conducted in a closed loop wind tunnel, where the heat exchanger was mounted at 45 degree inclination angle. The wet surface heat transfer coefficient was reduced following the procedure given in ARI 420-81. During the course, new definitions of the $\varepsilon$-NTU applicable to enthalpy driving system were introduced. The wet surface heat transfer coefficients were approximately equal to the dry surface values. However, the friction factors were approximately 120% to 170% higher than those of the dry surface. Both the heat transfer coefficient and the friction factor of the wet surface increased as the relative humidity increased, fin pitch decreased, and the number of row decreased, although the difference was not large.

• International Journal of Aeronautical and Space Sciences
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• 제17권3호
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• pp.352-357
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• 2016

An investigation of ribbed divergent channel was undertaken to determine the effect of rib pitch to height ratio on total friction factor and heat transfer results in the fully developed regime. The ribbed divergent rectangular channel with the channel exit hydraulic diameter ($D_{ho}$) to inlet channel hydraulic diameter ($D_{hi}$) ratio of 1.16 with wall inclination angle of 0.72 deg, at which the ratios (p/e) of 6,10, and 14 are considered. The ribbed straight channel of $D_{ho}/D_{hi}=1.0$ were also used. The ribbed divergent wall is manufactured with a fixed rib height (e) of 10 mm and the ratio of rib spacing (p) to height 6, 10, and 14. The measurement was run with range of Reynolds numbers from 24,000 to 84,000. The comparison shows that the ratio of p/e=6 has the greatest thermal performance in the divergent channel under two constraints; identical mass flow rate and identical pressure drop.

• 대한추나의학회지
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• 제4권1호
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• pp.89-98
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• 2003

The multiple acupuncture techniques have been used to relieve the pain of lateral ankle sprain. Recently, early functional rehabilitation is emphasized in rehabilitative concepts using active ROM, facilitated proprioception, alphabet exercise and so forth. Similarly, in oriental rehabilition medicine, traditional movement technique called "Dong-Ki" has been used to relieve pain of ankle sprain. So we used "Dong-Ki" technique with SSP(silver spike point) electrotherapy transformed from alphabet exercise and evaluated the effects in method of randomized controlled trials. Methods : 27 outpatients with lateral ankle sprains were randomized into two groups : 15 samples and 12 controls. Sample group was treated with "Dong-Ki" technique(writing his name with foot) with SSP electrotherapy to relieve pain during additionally. "Dong-KI". Outcomes were measured by 10cm VAS and ankle circumference(cm). Results : In terms of VAS, Sample group had inclination of pain relieving but not significantly meaningful. In terms of ankle circumference measurement, Sample group showed significantly improved.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.507-510
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• 2004

Oblique ion-induced secondary electron emission coefficient(${\gamma}$) with low energy ..and work function ${\phi}_{\omega}$(${\theta}$ = 0 and ${\theta}$ = 20) of the MgO thin film in AC-PDPs has been measured by ${\gamma}$-FIB system. The MgO thin film has been deposited from sintered material under electron beam evaporation method. The energy of $He^+$ ions used has been ranged from 50eV to 150eV. Oblique ion beam has been chosen to be 10 degree, 20 degree and 30 degree. It is found that the higher secondary electron emission coefficient(${\gamma}$) has been achieved by the higher oblique ion beam up to inclination angle of 30 degree than the perpendicular incident ion beam.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권5호
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• pp.459-466
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• 2010

Alveolar distraction osteogenesis (ADO) has been regarded as an acceptable treatment for the alveolar bone deficiency. For ADO at anterior maxillary area, the vector should be oriented to forward and down-ward direction to get an adequate occlusion with mandibular teeth and to increase bone length and width for implant placement. However, the conventional commercial distraction devices for ADO are designed to allow mainly downward movement of alveolar segment, even though a forward movement can be obtained a little by controlling of inclination of device. To make ADO with controllable bidirectional vector possible, we used customized devices using self-manufactured ABDUL (Alveolar Bone Distractor Using Lag screw principle) and commercial orthodontic palatal expansion device ($Hyrex^{(R)}$). In all cases (n = 4), ADO could be performed successfully and dental implants were able to placed with adequate occlusion. We report the procedures, advantages and disadvantages of these methods.

• 한국수학교육학회지시리즈A:수학교육
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• 제38권2호
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• pp.129-144
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• 1999

The purpose of our work is to developing the program of math. camp to improve underachiever's mathematical disposition. To do this, the following research were taken; (1)Analysis of current status of programs for underachievers (2)Analysis of inclination to mathematics(We collected the data from 2 classes of middle schools) (3)Prepare and apply the program of math. camp for the students including underachievers, and then analysis the effect of the math. camp The results of this study is as follows; (1)Only 40% of investigated schools have their own programs for underachievers. But almost all general high schools do not have such programs because students do not want. More than half of the investigated teachers suggested that the most important thing for underachievers is the induction of motivation for mathematics. (2)Many students dislike mathematics from 5∼6 grade of elementary school, and more than 50% of students think that 'measure' and 'equations' items are difficult. (3) After attending the math. camp based on the games and activities in small groups, the students in the middle-ranking group showed more positive reactions against the items of mathematical disposition and attitude tests. The students in the row-ranking group were improved in the 'self-confidence' and 'will' items of mathematical disposition test and in the 'superiority' and 'interest' items of mathematical attitude test.