• Proceedings of the KIEE Conference
• /
• 1999.11b
• /
• pp.322-324
• /
• 1999

This paper presents the methodology of measuring the 22.9[kV] bus load characteristics for verifying the bus load model developed with equivalent load aggregation of load components, and the analysis of 22.9[kV] load data.

• Journal of the Korean Society of Safety
• /
• v.17 no.4
• /
• pp.178-183
• /
• 2002

The purpose of this study was to quantitatively investigate the effects of external load upper extremity posture on perceived discomfort. An experiment was conducted for measuring discomfort scores depending upon external loads and upper extremity postures, in which the free modules and numeric estimate method of the magnitude estimation was adopted as a tool for obtaining discomfort ratings. The upper extremity postures were controlled by wrist flexion/extension, elbow foexion, shoulder flexion, and shoulder adduction/abduction. The results showed that all experimental variables except shoulder adduction/abduction were significant at ${\alpha}$=0.01 or 0.05. The effect of external load was very much larger than that of upper extremity postures. Therefore, it is recommended that a new posture classification scheme taking effect of external load to into consideration be developed for quantifying postural load.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1362-1372
• /
• 1999

Ray-tracing algorithm can synthesize photo-realistic image, but its computational cost is high. Fast image synthesis based on ray-tracing is one of the most important topics in computer graphics. There are two methods for high speed ray-tracing. First this paper discusses various load distribution and scheduling of multiprocessor for high sped ray-tracing. Then this paper proposes load distribution strategies based on them, implements and evaluates it on multiprocessor. The experiment results show that the proposed method can solve the unbalanced load problem of dynamic load distribution, and scan line method and dot method among a kind of static load distribution strategies disperse the load efficiently.

• Educational Technology International
• /
• v.10 no.2
• /
• pp.145-166
• /
• 2009

The purpose of this study was to investigate why advance organizers (AO) are effective in promoting comprehension and mental model formation in terms of cognitive load. Two experimental groups: a concept-map AO group and a key-word AO group and one control group were used. This study considered cognitive load in view of Baddeley's working memory model: central executive (CE), phonological loop (PL), and visuo-spatial sketch pad (VSSP). The present experiment directly examined cognitive load using dual task methodology. The results were as follows: central executive (CE) suppression task achievement for the concept map AO group was higher than the key word AO group and control group. Comprehension and mental model construction for the concept map AO group were higher than the other groups. These results indicated that the superiority of concept map AO owing to CE load decrement occurred with comprehension and mental model construction in learning. Thus, the available resources produced by CE load reduction may have been invested for comprehension and mental model construction of learning contents.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.4
• /
• pp.153-158
• /
• 2013

The purpose of this study is to investigate the performance characteristics of the counterflow exhaust heat recovery device for the applied gasoline engines. The EHRS device is installed behind the catalyst. This study investigates the engine warm-up characteristic, the exhaust noise characteristic, the back-pressure characteristic. The engine warm-up characteristics is (load 0%, load 10%, load 20%) in (idle, 1000rpm, 1500rpm, 2000rpm, 2500rpm) conditions by measuring the time it warmed up, coolant temperature ($25^{\circ}C{\sim}80^{\circ}C$) until the performance evaluation is performed. The wide open throttle and the coast down the exhaust noise and the back-pressure characteristic experiment repeated twice. The test conditions is 950rpm~6,050rpm proceed experiment repeated 3-5 times. Load 0% idle conditions except the results improved engine warm-up characteristics. The exhaust noise obtain similar results the BASE+EHRS W/O_FRT_MUFF with BASE and back-pressure to obtain similar results BASE+EHRS W/O_FRT_ MUFF with BASE+EHRS.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.51 no.4
• /
• pp.159-164
• /
• 2002

This paper presents the design and fabrication of a high-Tc superconducting (HTS) power supply for charging of the HTS magnet load, and its characteristics have been analyzed through experiments. HTS power supply consists of two heaters, an electromagnet, a Bi-2223 solenoid and a Bi-2223 pancake magnet load. In this experiment, 331 mH electromagnet and 0.8 A dc heater current were used, and 8.5 sec and 17 sec were used for pumping period. Mechanism of the superconducting switch is used for heater-trigger. In order to measure the pumping-current with respect to the magnet flux changes, hall sensor was installed at the center of the Bi-2223 pancake load. The experimental observations have been compared with the theoretical predictions. In this experiment, the pumping-current has reached about 1.2 A. In computer simulation, the maximum pumping-current of the system has been predicted to be about 2.7 A.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.15 no.2
• /
• pp.50-57
• /
• 2019

This paper investigates deformation characteristics of gas pipeline using the in-plane bending experiment and finite element analysis of a pipe bend. The effect of the bending angle and internal pressure on the deformation characteristics is analyzed. The pipe bend used in this study is API 5L X65 (out diameter: 20 inch) material with the thickness of 11.9 mm. The maximum load, displacement at maximum load, angle and local strain of 90° pipe bend are obtained from the in-plane bending experiment. Comparison between FE results and experimental data shows overall good agreements. In addition, the deformation characteristics of 22.5° and 45° pipe bend are calculated using the finite element analysis. As a result, the effect of the bend angle on the deformation characteristics is discussed.

• Journal of the Korean Society of Industry Convergence
• /
• v.10 no.1
• /
• pp.5-14
• /
• 2007

It is necessary for development of drawing product with press to have suitable material selection & all process design and the problem during press process has been cleared from judgement of experience & trial and error. Recently we can estimate press process result from computer aided design & FEM. But we can get more reliable result when we can put more precise process variants during FEM. In case of using a drawbead that is used for the material inflow, it is considered for us to put material property, other analysis condition & friction figure when material is passing through the drawbead for better FEM. From our study, we have drawn an analogy bead connection depth, friction figure & drawing and restraining load according to kinds of lubrication from experiment & FEM for the drawbead. We applied above result to the drawing experiment & FEM and confirmed the validity. We could notice the relation between friction figure & drawing load and the friction figure variation according to kinds of lubrication. It is expected to draw more precise analogy that can be used for real process due to more precise process variants application to FEM.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2006.10a
• /
• pp.87-94
• /
• 2006

In this study we carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.838-841
• /
• 2005

This study was carried out to analyze the effect of wind load on the structural stability of a 50ton articulation type container crane using wind tunnel test and provide a container crane designer with data which can be used in a wind resistance design of an articulation type container crane assuming that a wind load 75m/s wind velocity is applied in an articulation type container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of an articulation type container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.